ABSTRACT
Respiratory syncytial virus (RSV) is a major cause of acute respiratory infection (ARI), though its healthcare burden and costs are insufficiently described among adults in the United Kingdom. With the recent availability of vaccines, understanding RSV-related secondary care burden is essential. Routinely collected adult ARI hospitalization data between 2018 and 2023 from four English National Health Service (NHS) trusts and a Scottish Health Board were linked to RSV, influenza, and coronavirus disease 2019 (COVID-19) microbiology tests and results. ARI incidence risk and ARI-related hospitalizations overall and per pathogen were described (including mortality, hospitalization length of stay [LoS], intensive care unit [ICU] admissions/LoS, and costs). RSV-positive microbiology tests and International Classification of Diseases (ICD)-10 RSV diagnoses were compared. In both settings, incidence risk of first ARI hospitalizations increased from 2018/19 to 2022/23. Of RSV-tested hospitalizations, 7.0% (England) and 4.1% (Scotland) had an RSV-positive test. Of these, 7.4% and 8.0% died in hospital, respectively; similar proportions were observed for influenza (5.5% and 5.0%). In England and Scotland, RSV-positive hospitalization LoS was 5 and 6 d, comparable to COVID-19 (8 and 10) and influenza (4 and 3). ICU admittance and direct costs per hospitalization were generally comparable across pathogens. In England and Scotland, 63.5% and 33.7% of RSV-positive hospitalizations had an RSV ICD-10 code, respectively. Among English and Scottish adults, RSV-positive hospitalizations had substantial healthcare resource utilization, comparable to COVID-19- and influenza-positive hospitalizations. ICD-10 codes are limited proxies for identifying RSV hospitalizations. Broadening RSV adult vaccination recommendations may reduce the RSV secondary care burden.
KEYWORDS: Respiratory syncytial virus, burden of disease, acute respiratory infection, influenza, COVID-19, hospital admission
Introduction
Respiratory syncytial virus (RSV) is a seasonal respiratory virus associated with a high risk of hospitalization and mortality, particularly among older adults and those with chronic conditions.1–3 Alongside influenza and coronavirus disease 2019 (COVID-19), RSV is a major contributor to acute respiratory infection (ARI), incurring a significant burden to healthcare systems, predominantly from hospitalizations.4–7 In the UK, RSV hospitalization rates are estimated at 321 per 100,000 person years in individuals ≥60 y of age (YOA).8
To protect against lower respiratory tract disease (LRTD) caused by RSV, the European Medicines Agency (EMA) approved adjuvanted RSVPreF3 for adults ≥60 YOA and at-risk adults 50–59 YOA (2023), RSVPreF for adults ≥18 YOA (2023), and mRNA-1345 for adults ≥60 YOA and at-risk adults 18–49 YOA (2024). The UK Medicines and Healthcare products Regulatory Agency (MHRA) approved these vaccines in accordance with official EMA recommendations, and a free vaccination program is available for adults 75–79 YOA in the UK.9–12
Quantifying the RSV health and economic burden among adults is essential to inform policymakers on the importance of RSV preventative measures in adults ≥18 YOA. Current UK literature on RSV burden among adults is limited and outdated.13 One study indicated that between 2001 and 2009, annual direct medical costs to manage ARIs in adults 19–49 YOA was approximately £175 million.6 Between 1995 and 2009 in the UK, an average of 17,799 hospitalizations and 8,482 deaths per RSV season were attributed to RSV among adults ≥18 YOA.14 Furthermore, this burden may be underestimated due to under-testing and under-reporting, caused by ambiguous disease classification, lack of routine testing, and poor test sensitivity.15–18
This study explored the incidence risk of ARI, healthcare resource use (HCRU), and direct costs of RSV management in English and Scottish secondary care hospital settings between 2018 and 2023 among adults ≥18 YOA. The burden of RSV-positive hospitalizations was evaluated against overall ARI-related hospitalizations and hospitalizations for COVID-19 and/or influenza. Additionally, the concordance of RSV International Classification of Diseases 10th Revision (ICD-10) coded diagnoses versus positive microbiology tests was described.
Materials and methods
Data collection
This database study was an observational, retrospective, and multi-center cohort study which analyzed the routine electronic health record (EHR) data of adults from secondary care settings in England and Scotland. Results are reported over five consecutive annual cycles, from 1st April to 31st March for 2018/19, 2019/20, 2020/21, 2021/22, and 2022/23. EHR data from the Arcturis Real-World Data Network database of four England National Health Service (NHS) trusts (Oxford University Hospital NHS Foundation Trust, Milton Keynes University Hospital NHS Foundation Trust, Hampshire Hospital NHS Foundation Trust, and Chelsea and Westminster Hospital NHS Foundation Trust) and a health board in Scotland (NHS Greater Glasgow and Clyde Health Board [NHSGGC]) were analyzed separately.
Index date was defined as the hospital entry date of an ARI ICD-10 coded hospitalization that fell within the observational period, using the ICD-10 codes in Table S1. Eligible individuals were ≥18 YOA at index and hospitalized with an ARI diagnosis within the observational period. Anonymized data on demographics, microbiology tests, diagnoses, procedures (OPCS Classification of Interventions and Procedures v4), ward movements (intensive care unit [ICU] admissions), recorded episodes, and spells were extracted.
Hospitalizations were attributed to the annual cycle in which the index date fell. Tests dated ≤7 d after a hospitalization were associated with that stay, accounting for recording delays and in line with the UK Health Security Agency’s target RSV test turnaround time; tests without dates, or dates falling outside the 7-d window following a hospitalization, were excluded.19 Test dates were attributed to the date of the test result, and tests linked to multiple hospitalizations were attributed to the closest prior stay.
Data analysis
Sub-cohort analysis
Among those hospitalized with an ARI diagnosis, a sub-cohort of individuals who underwent microbiological testing for RSV, COVID-19, or influenza during hospitalization were identified (pathogen-tested sub-cohort). Individuals who tested positive were further sub-grouped by pathogen type (Table S2). Hospitalizations could be included in multiple sub-groups if the patient tested positive for multiple relevant pathogens.
Characteristics of ARI-hospitalized adults
ARI hospitalizations over the observation period were stratified by sex, age, ARI diagnosis position and type, patient risk-group, comorbidities (either primary or secondary diagnoses and recorded ≤12 months prior to index; ICD-10 codes for comorbidities are listed in Table S3), and annual cycle. In line with a previously published RSV clinical trial, individuals were considered high-risk if they had asthma, cardiac disorder, chronic kidney disease (CKD), chronic liver disease, chronic obstructive pulmonary disease (COPD) or other chronic restrictive pulmonary diseases, or diabetes recorded in the year prior to index; individuals without these comorbidities were considered non-high-risk.20
Incidence risk of first ARI hospitalization per annual cycle
Incidence risk of first ARI hospitalization, defined as first ARI hospitalization per annual cycle for each eligible patient, was estimated. The number of first ARI hospitalizations was divided by the adult population at risk of being hospitalized for ARI, as defined by the average of the 2018 to 2020 adult catchment populations of the included hospitals (Appendix A).21,22 Incidence risk is reported per 1,000 individuals alongside 95% confidence intervals (CI), estimated using the normal approximation method for proportions. Due to the descriptive nature of these analyses, no formal hypothesis testing was undertaken.
In-hospital mortality
An in-hospital death was defined as an individual who died during hospitalization, or had their death recorded within 7 d of discharge, accounting for potential reporting delays. Percentage of in-hospital deaths among ARI-related individuals are reported with associated 95% CI.
HCRU of ARI-associated hospitalizations
Median length of stay (LoS) and interquartile range (IQR) of hospitalization and ICU admissions were calculated as the difference between the respective start and end dates. Proportions of ARI hospitalizations with an associated ICU admission were also reported.
If only year (or year and month) of death was provided and a patient’s last recorded date in other medical records was in the same timeframe, that recorded date was adopted as the individual’s date of death. If there was no medical record in the reported year of death, the midpoint of the year (1st July) was assumed as the individual’s date of death. If only death year and death month were provided, the individual was assumed to have died at the approximate midpoint (15th) of the recorded month. Where only the year of death was provided prior to other recorded years in the medical records, the data were omitted from the analysis as implausible.
Direct medical cost per hospitalization
Unit costs for diagnoses and procedures were derived from NHS secondary care tariffs for healthcare resource groups (HRG), with costs based on HRG4+ 2022/23 National Costs Grouper.23 For HRGs with no nationally agreed tariff, patient-level cost data for the relevant HRG codes were averaged and applied as cost per patient hospitalization. Mean cost and standard deviation (SD) per hospitalization are reported in Great British Pounds (£, GBP).
RSV microbiology testing versus ICD-10 coding
To describe the concordance of RSV ICD-10 coded diagnoses and microbiology test results, RSV hospitalizations with an RSV microbiology test and/or an ICD-10 diagnosis (Table S4) were compared.
Ethical considerations
This study used anonymized EHR data from the Arcturis Real-World Data Network database, which has received research database ethical approval from the NHS Health Research Authority Yorkshire & The Humber – Leeds East Research Ethics Committee (research ethics committee [REC] reference: 24/YH/0164). An anonymized dataset was provided by the West of Scotland Safe Haven research database service at NHSGGC under REC approval 22/WS/0163. To protect patient privacy, some results are censored. Categories with fewer than five patients are reported as “<5” with no percentages, and additional categories may be masked using a range of five (inclusive) to prevent back-calculation. No results are presented for any annual cycle or sub-cohort with fewer than ten patients. Additionally, categories of categorical data were collapsed, where required, for example using 10-y age bands rather than 5 y. For the hospitalization cost analysis, summary statistics were reported only when more than 20 observations contributed.
Results
Characteristics of ARI-hospitalized adults
In English trusts, 114,585 individuals had 164,294 hospitalizations with an ARI-specific ICD-10 code during the observational period, of which 56.2% (n = 92,305) were tested for RSV, COVID-19 and/or influenza. In NHSGGC, 90,522 individuals had 144,108 ARI-related hospitalizations, of which 51.2% (n = 73,733) were tested for RSV, COVID-19, and/or influenza (Table 1).
Table 1.
ARI-related hospitalizations by patient subgroup and annual cycle in the ARI-hospitalized cohort and pathogen-tested, RSV-positive, COVID-19-positive, and influenza-positive sub-cohorts in England and Scotland.
| Characteristics | All ARI (ICD-10 diagnoses) | Pathogen-testeda | RSV-positive | COVID-19-positive | Influenza-positive |
|---|---|---|---|---|---|
| English trusts | |||||
| Total, n | 164,294 | 92,305 | 861 | 26,185 | 3,123 |
| Sex, n (%) | |||||
| Female | 84,702 (51.6) | 46,661 (50.6) | 479 (55.6) | 12,632 (48.2) | 1,803 (57.7) |
| Male | 79,587 (48.4) | 45,641 (49.4) | 382 (44.4) | 13,552 (51.8) | 1,319 (42.2) |
| Missing | 5 (0.0) | 3 (0.0) | 0 (0.0) | 1 (0.0) | 1 (0.0) |
| Age group (years), n (%) | |||||
| 18–49 | 34,512 (21.0) | 17,181 (18.6) | 98 (11.4) | 5,596 (21.4) | 996 (31.9) |
| 50–59 | 17,727 (10.8) | 9,994 (10.8) | 120 (13.9) | 3,193 (12.2) | 341 (10.9) |
| 60–64 | 10,987 (6.7) | 6,278 (6.8) | 81 (9.4) | 1,776 (6.8) | 215 (6.9) |
| 65–69 | 12,671 (7.7) | 7,112 (7.7) | 82 (9.5) | 1,881 (7.2) | 189 (6.1) |
| 70–74 | 16,987 (10.3) | 9,721 (10.5) | 93 (10.8) | 2,461 (9.4) | 252 (8.1) |
| 75–79 | 18,914 (11.5) | 10,879 (11.8) | 116 (13.5) | 2,888 (11.0) | 345 (11.0) |
| 80–84 | 19,221 (11.7) | 11,434 (12.4) | 88 (10.2) | 2,994 (11.4) | 294 (9.4) |
| 85–89 | 17,918 (10.9) | 10,538 (11.4) | 96 (11.1) | 2,895 (11.1) | 278 (8.9) |
| ≥90 | 15,357 (9.3) | 9,168 (9.9) | 87 (10.1) | 2,501 (9.6) | 213 (6.8) |
| ARI diagnosis order, n (%) | |||||
| Primary | 95,264 (58.0) | 53,706 (58.2) | 576 (66.9) | 16,211 (61.9) | 2361 (75.6) |
| Additional | 69,030 (42.0) | 38,599 (41.8) | 285 (33.1) | 9,974 (38.1) | 762 (24.4) |
| ARI type, n (%) | |||||
| URTD | 9,297 (5.7) | 2,884 (3.1) | 65 (7.5) | 216 (0.8) | 29 (0.9) |
| LRTD | 122,415 (74.5) | 68,930 (74.7) | 637 (74.0) | 13,199 (50.4) | 3,013 (96.5) |
| Both | 649 (0.4) | 389 (0.4) | 40 (4.6) | 49 (0.2) | 28 (0.9) |
| Not specified | 31,933 (19.4) | 20,102 (21.8) | 119 (13.8) | 12,721 (48.6) | 53 (1.7) |
| Comorbidities, n (%) | |||||
| Other CRPD | 24,320 (14.8) | 15,275 (16.5) | 128 (14.9) | 3,217 (12.3) | 323 (10.3) |
| Asthma | 20,363 (12.4) | 11,157 (12.1) | 168 (19.5) | 2,714 (10.4) | 523 (16.7) |
| COPD | 35,449 (21.6) | 19,645 (21.3) | 199 (23.1) | 3,610 (13.8) | 552 (17.7) |
| Cardiac disorders | 68,031 (41.4) | 39,967 (43.3) | 401 (46.6) | 9,610 (36.7) | 1,017 (32.6) |
| Chronic liver disease | 5,001 (3.0) | 3,066 (3.3) | 22 (2.6) | 795 (3.0) | 62 (2.0) |
| Chronic kidney disease | 25,597 (15.6) | 15,928 (17.3) | 174 (20.2) | 4,260 (16.3) | 378 (12.1) |
| Diabetes | 32,916 (20.0) | 19,416 (21.0) | 186 (21.6) | 5,507 (21.0) | 542 (17.4) |
| Stroke | 4,478 (2.7) | 2,749 (3.0) | 17 (2.0) | 740 (2.8) | 56 (1.8) |
| Immunocompromised | 39,618 (24.1) | 23,189 (25.1) | 264 (30.7) | 5,817 (22.2) | 584 (18.7) |
| Patient risk-groupb, n (%) | |||||
| High-risk | 108,409 (66.0) | 62,373 (67.6) | 644 (74.8) | 15,567 (59.5) | 1,889 (60.5) |
| Non-high-risk | 55,885 (34.0) | 29,932 (32.4) | 217 (25.2) | 10,618 (40.6) | 1,234 (39.5) |
| Annual cycle, n (%) | |||||
| 2018/19 | 29,748 (18.1) | 3,959 (4.3) | 196 (22.8) | 0 (0.0) | 754 (24.1) |
| 2019/20 | 32,958 (20.1) | 5,727 (6.2) | 201 (23.3) | 1,068 (4.1) | 572 (18.3) |
| 2020/21 | 29,534 (18.0) | 25,832 (28.0) | <5 | 9,143 (34.9) | <5 |
| 2021/22 | 32,733 (19.9) | 28,229 (30.6) | 55–58 | 7,735 (29.5) | 68–71 |
| 2022/23 | 39,321 (23.9) | 28,558 (30.9) | 405 (47.0) | 8,239 (31.5) | 1,725 (55.2) |
| Scotland NHSGGC | |||||
| Total, n | 144,108 | 73,733 | 799 | 17,442 | 3,905 |
| Sex, n (%) | |||||
| Female | 80,908 (56.1) | 41,255 (56.0) | 518 (64.8) | 9,083 (52.1) | 2,324 (59.5) |
| Male | 63,200 (43.9) | 32,478 (44.0) | 281 (35.2) | 8,359 (47.9) | 1,581 (40.5) |
| Missing | 0 | 0 | 0 | 0 | 0 |
| Age group (years), n (%) | |||||
| 18–49 | 30,676 (21.3) | 11,959 (16.2) | 118 (14.8) | 2,983 (17.1) | 1,372 (35.1) |
| 50–59 | 20,097 (13.9) | 9,935 (13.5) | 124 (15.5) | 2,171 (12.4) | 591 (15.1) |
| 60–64 | 12,777 (8.9) | 6,951 (9.4) | 91 (11.4) | 1,479 (8.5) | 359 (9.2) |
| 65–69 | 13,130 (9.1) | 7,132 (9.7) | 69 (8.6) | 1,485 (8.5) | 315 (8.1) |
| 70–74 | 15,453 (10.7) | 8,379 (11.4) | 84 (10.5) | 1,839 (10.5) | 311 (8.0) |
| 75–79 | 16,050 (11.1) | 9,053 (12.3) | 93 (11.6) | 2,051 (11.8) | 334 (8.6) |
| 80–84 | 15,560 (10.8) | 8,641 (11.7) | 102 (12.8) | 2,217 (12.7) | 296 (7.6) |
| 85–89 | 12,255 (8.5) | 6,985 (9.5) | 69 (8.6) | 1,946 (11.2) | 203 (5.2) |
| ≥90 | 8,110 (5.6) | 4,698 (6.4) | 49 (6.1) | 1,271 (7.3) | 124 (3.2) |
| ARI diagnosis order, n (%) | |||||
| Primary | 104,782 (72.7) | 53,342 (72.3) | 619 (77.5) | 13,126 (75.3) | 3,394 (86.9) |
| Additional | 39,326 (27.3) | 20,391 (27.7) | 180 (22.5) | 4,316 (24.7) | 511 (13.1) |
| ARI type, n (%) | |||||
| URTD | 8,319 (5.8) | 1,804 (2.4) | 22–26 | 105 (0.6) | 38 (1.0) |
| LRTD | 107,894 (74.9) | 56,316 (76.4) | 637 (79.7) | 7,448 (42.7) | 3,742 (95.8) |
| Both | 256 (0.2) | 152 (0.2) | <5 | 15 (0.1) | 13 (0.3) |
| Not specified | 27,639 (19.2) | 15,461 (21.0) | 136 (17.0) | 9,874 (56.6) | 112 (2.9) |
| Comorbidities, n (%) | |||||
| Other CRPD | 8,287 (5.8) | 4,665 (6.3) | 44 (5.5) | 670 (3.8) | 124 (3.2) |
| Asthma | 9,109 (6.3) | 5,232 (7.1) | 79 (9.9) | 981 (5.6) | 296 (7.6) |
| COPD | 28,560 (19.8) | 15,362 (20.8) | 172 (21.5) | 2,384 (13.7) | 613 (15.7) |
| Cardiac disorders | 32,095 (22.3) | 17,631 (23.9) | 189 (23.7) | 3,716 (21.3) | 558 (14.3) |
| Chronic liver disease | 4,002 (2.8) | 2,160 (2.9) | 20 (2.5) | 475 (2.7) | 49 (1.3) |
| Chronic kidney disease | 11,608 (8.1) | 6,627 (9.0) | 78 (9.8) | 1,555 (8.9) | 205 (5.2) |
| Diabetes | 15,837 (11.0) | 8,856 (12.0) | 102 (12.8) | 2,268 (13.0) | 289 (7.4) |
| Stroke | 3,656 (2.5) | 2,056 (2.8) | 16 (2.0) | 686 (3.9) | 50 (1.3) |
| Immunocompromised | 21,510 (14.9) | 12,091 (16.4) | 157 (19.6) | 2,414 (13.8) | 372 (9.5) |
| Patient risk-groupb, n (%) | |||||
| High-risk | 67,125 (46.6) | 37,182 (50.4) | 413 (51.7) | 7,833 (44.9) | 1,399 (35.8) |
| Non-high-risk | 76,983 (53.4) | 36,551 (49.6) | 386 (48.3) | 9,609 (55.1) | 2,506 (64.2) |
| Annual cycle, n (%) | |||||
| 2018/19 | 30,007 (20.8) | 3,911 (5.3) | 167 (20.9) | 14 (0.1) | 694 (17.8) |
| 2019/20 | 30,965 (21.5) | 6,964 (9.4) | 339 (42.4) | 687 (3.9) | 915 (23.4) |
| 2020/21 | 24,790 (17.2) | 19,533 (26.5) | 7 (0.9) | 5,522 (31.7) | 7 (0.2) |
| 2021/22 | 27,543 (19.1) | 21,314 (28.9) | 31 (3.9) | 5,629 (32.3) | 177 (4.5) |
| 2022/23 | 30,803 (21.4) | 22,011 (29.9) | 255 (31.9) | 5,590 (32.0) | 2,112 (54.1) |
aSome hospitalizations contain tests for multiple pathogens. bIndividuals were considered high-risk if they had asthma, cardiac disorder, chronic kidney disease, chronic liver disease, chronic obstructive pulmonary disease, other chronic restrictive pulmonary diseases, or diabetes up to 12 months prior to index date; individuals with an absence of a specified comorbidity were considered non-high-risk. Risk-group distribution is further broken down by older adult age group (50–64, 65–79, and ≥80 y) in Supplementary Table 5. ARI, acute respiratory infection; COPD, chronic obstructive pulmonary disease; CRPD, chronic restrictive pulmonary disease; COVID-19, coronavirus disease 2019; ICD-10, International Classification of Diseases 10th Revision; LRTD, lower respiratory tract disease; NHSGGC, National Health Service Greater Glasgow and Clyde; RSV, respiratory syncytial virus; URTD, upper respiratory tract disease.
RSV was the least frequently tested, accounting for 13.3% (n = 12,320) of pathogen-tested hospitalizations in English trusts and 26.2% (n = 19,285) in NHSGGC. Most pathogen-tested hospitalizations included a COVID-19 test, at 91.6% (n = 84,546) and 87.6% (n = 64,622) in English trusts and NHSGGC, respectively. Testing for influenza was higher in NHSGGC (62.5%, n = 46,109) compared with English trusts (22.9%, n = 21,135).
Of the hospitalizations tested for RSV, 7.0% (n = 861) and 4.1% (n = 799) had an RSV-positive test in English trusts and NHSGGC, respectively; 31.0% (n = 26,185) and 26.9% (n = 17,442) of COVID-19-tested hospitalizations had a COVID-19-positive test and 14.8% (n = 3,123) and 8.5% (n = 3,905) of influenza-tested hospitalizations had an influenza-positive test.
Demographic characteristics
In English trusts and NHSGGC, 51.6% and 56.1% of the ARI-related hospitalizations were among females (Table 1).
Overall, 21.0% of ARI-related hospitalizations in English trusts and 21.3% in NHSGGC were in individuals <50 YOA at index, with high proportions (53.8% and 46.8%) in individuals ≥70 YOA (Table 1). RSV-positive hospitalizations had the oldest age distribution of the three pathogens, with those ≥50 YOA accounting for 88.6% and 85.2% of all RSV-positive hospitalizations in English trusts and NHSGGC, respectively, versus 78.6% and 82.9% for COVID-19-positive hospitalizations and 68.1% and 64.9% for influenza-positive hospitalizations (Figure 1).
Figure 1.
Total ARI-related hospitalizations by age distribution in the RSV-positive, COVID-19-positive, and influenza-positive sub-cohorts in (A) English trusts and (B) NHSGGC.
ARI, acute respiratory infection; COVID-19, coronavirus disease 2019; NHSGGC, National Health Service Greater Glasgow and Clyde; RSV, respiratory syncytial virus.
Among ARI-related hospitalizations in English trusts and NHSGGC, commonly reported comorbidities included cardiac disorders (41.4% and 22.3%, respectively), conditions related to a compromised immune system (24.1% and 14.9%), COPD (21.6% and 19.8%), diabetes (20.0% and 11.0%), and CKD (15.6% and 8.1%) (Figure 2). When stratifying by risk group, a higher proportion of hospitalizations occurred among high-risk versus non-high-risk individuals across the three age groups examined (50–64, 65–79, and ≥80 y) in English trusts. This trend was also observed in the 65–79 and ≥80 y age groups in NHSGGC (Table S5).
Figure 2.
Proportion of adults hospitalized with an ARI ICD-10 diagnosis with comorbidities of interest per sub-cohort in England and Scotland.
(a) Individuals hospitalized with an ARI ICD-10 code according to Table S2. (b) Pathogen-tested cohort comprised individuals hospitalized with an ARI ICD-10 code according to Table S2 and who were tested for RSV, COVID-19, and/or influenza. ARI, acute respiratory infection; COPD, chronic obstructive pulmonary disease; COVID-19, coronavirus disease 2019; ICD-10, International Classification of Diseases 10th Revision; NHSGGC, National Health Service Greater Glasgow and Clyde; RSV, respiratory syncytial virus.
Incidence risk of first ARI hospitalization per age group
Of the 114,585 and 90,522 first ARI hospitalizations in English trusts and NHSGCC, respectively, incidence increased with age. In English trusts, incidence risk of first ARI hospitalization was 6.06 (95% CI: 5.71–6.41) per 1,000 individuals among those aged 18–49 y and 120.36 (113.00–127.73) per 1,000 individuals among those aged ≥90 y. Similarly, incidence risk was 9.47 (8.89–10.06) and 96.79 (90.64–102.94) per 1,000 individuals among those aged 18–49 y and ≥85 y in NHSGCC, respectively (Table 2).
Table 2.
Incidence risk of first ARI-related hospitalization by age group and annual cycle in England and Scotland between 2018 and 2023.
| First ARI-related hospitalization (N) | Population at riska | Incidence per 1,000 populationb (95% CI) |
|
|---|---|---|---|
| English trusts | |||
| Age group (years) | |||
| 18–49 | 28,303 | 934,175 | 6.06 (5.71–6.41) |
| 50–59 | 13,056 | 269,799 | 9.68 (8.87–10.49) |
| 60–64 | 7,603 | 106,808 | 14.24 (12.69–15.78) |
| 65–69 | 8,531 | 93,142 | 18.32 (16.47–20.17) |
| 70–74 | 10,998 | 90,370 | 24.34 (22.21–26.47) |
| 75–79 | 11,833 | 62,004 | 38.17 (35.08–41.26) |
| 80–84 | 12,336 | 45,072 | 54.74 (50.62–58.86) |
| 85–89 | 11,716 | 27,621 | 84.83 (79.01–90.66) |
| ≥90 | 10,209 | 16,964 | 120.36 (113.00–127.73) |
| Annual cycle | |||
| 2018/19 | 23,959 | 1,645,955 | 14.56 (14.37–14.74) |
| 2019/20 | 26,512 | 1,645,955 | 16.11 (15.92–16.3) |
| 2020/21 | 24,521 | 1,645,955 | 14.90 (14.71–15.08) |
| 2021/22 | 27,093 | 1,645,955 | 16.46 (16.27–16.65) |
| 2022/23 | 31,705 | 1,645,955 | 19.26 (19.05–19.47) |
| Scotland NHSGGC | |||
| Age group (years) | |||
| 18–49 | 24,210 | 511,085 | 9.47 (8.89–10.06) |
| 50–59 | 12,774 | 164,408 | 15.54 (14.25–16.83) |
| 60–64 | 7,692 | 77,252 | 19.91 (17.80–22.03) |
| 65–69 | 7,376 | 62,476 | 23.61 (21.08–26.14) |
| 70–74 | 8,491 | 51,968 | 32.68 (29.50–35.86) |
| 75–79 | 8,813 | 39,148 | 45.02 (40.89–49.16) |
| 80–84 | 8,899 | 26,375 | 67.48 (61.77–73.19) |
| ≥85c | 12,267 | 25,347 | 96.79 (90.64–102.94) |
| Annual cycle | |||
| 2018/19 | 23,058 | 958,060 | 24.07 (23.76–24.37) |
| 2019/20 | 23,961 | 958,060 | 25.01 (24.7–25.32) |
| 2020/21 | 20,056 | 958,060 | 20.93 (20.65–21.22) |
| 2021/22 | 22,025 | 958,060 | 22.99 (22.69–23.29) |
| 2022/23 | 24,429 | 958,060 | 25.50 (25.18–25.81) |
aOverall NHS catchment populations were defined as the average catchment population aged ≥18 y at index date between 2018 and 2020. Catchment populations were held constant during the analysis period. To limit the study population to individuals aged ≥18 y, the 15–19 age group was multiplied by 0.4 to obtain an estimate of population aged 18–19. These data were added to the other adult age groups to obtain the overall adult population.
bNumber of ARI hospitalizations per 1,000 population. CI were calculated using the normal approximation method for proportions. Temporally overlapping hospitalizations were merged and attributed to hospital transfers. ARI, acute respiratory infection; CI, confidence interval; NHSGGC, National Health Service Greater Glasgow and Clyde.
cThe 2022 Scottish census only had a ≥85 y age group and so the 85–89 and ≥90 y age bands have been combined.
Incidence risk of first ARI hospitalization per annual cycle
Over the observation period, 133,790 and 113,529 first ARI hospitalizations per annual cycle were identified in English trusts and NHSGCC, respectively. In the 2018/19 annual cycle, incidence risk of first ARI hospitalization was estimated at 14.56 (95% CI: 14.37–14.74) per 1,000 individuals in English trusts and 24.07 (23.76–24.37) per 1,000 individuals in NHSGGC (Table 2). An upward trend was observed between 2020/21 and 2022/23, corresponding to the transition to the post-COVID-19 pandemic period. Incidence risk increased from 14.90 (14.71–15.08) to 19.26 (19.05–19.47) per 1,000 individuals in English trusts between 2020/21 and 2022/23. In NHSGGC, the increase was 20.93 (20.65–21.22) to 25.50 (25.18–25.81) per 1,000 individuals.
Mortality during ARI hospitalization
Of ARI-related hospitalizations, 14.4% (95% CI: 14.2–14.6; 16,540 deaths) and 15.2% (14.9–15.4, 13,727) of individuals had an in-hospital death in English trusts and NHSGGC, respectively (Table 3; Table S6). Among pathogen-tested hospitalizations, comparable rates were observed at 15.2% (15.0–15.5) in English trusts and 16.8% (16.5–17.1) in NHSGGC. Regarding the three pathogen-specific cohorts, COVID-19-positive hospitalizations had the highest percentage of in-hospital deaths at 13.9% (13.5–14.4) for English trusts and 18.6% (18.0–19.2) for NHSGCC, followed by RSV-positive hospitalizations at 7.4% (5.9–9.4) and 8.0% (6.1–9.9) and influenza-positive hospitalizations at 5.5% (4.8–6.4) and 5.0% (4.3–5.7), respectively. Mortality rates increased with age in both regions (Table S6).
Table 3.
HCRU and economic burden of ARI-related hospitalizations among adults in England and Scotland between 2018 and 2023.
| Characteristics | All ARI (ICD-10 diagnoses) | Pathogen-tested | RSV-positive | COVID-19-positive | Influenza-positive |
|---|---|---|---|---|---|
| English trusts | |||||
| Median hospitalization, days (IQR)a | 4 (1–12) | 6 (2–14) | 5 (2–12) | 8 (3–18) | 4 (1–10) |
| ICU stay, n (%) | 6,621 (4.0) | 4,795 (5.2) | 48 (5.6) | 1,467 (5.6) | 117 (3.7) |
| Median ICU duration, days (IQR)a | 5 (2–12) | 6 (2–13) | 3 (2–8) | 7 (3–16) | 6 (2–13) |
| Mean direct medical costs per hospitalization, £ (SD)b | 3,991.78 (4,393.73) | 4,473.48 (4,594.04) | 3,843.51 (3,500.24) | 3,842.30 (4,699.84) | 3,473.90 (3,640.44) |
| In-hospital mortality, % (95% CI)c | 14.4 (14.2–14.6) | 15.2 (15.0–15.5) | 7.4 (5.9–9.4) | 13.9 (13.5–14.4) | 5.5 (4.8–6.4) |
| Scotland NHSGGC | |||||
| Median hospitalization, days (IQR)a | 4 (1–11) | 6 (2–15) | 6 (2–12) | 9.5 (3–27) | 3 (1–8) |
| ICU stay, n (%) | 1,969 (1.4) | 1,564 (2.1) | 25 (3.1) | 559 (3.2) | 93 (2.4) |
| Median ICU duration, days (IQR)a | 6 (2–12) | 7 (3–14) | 11 (5–16) | 10 (4–18) | 6 (2–13) |
| Mean direct medical costs per hospitalization, £ (SD)b | 3,596.56 (6,068.43) | 3,901.08 (6,881.24) | 3,565.80 (5,593.54) | 4,758.00 (10,512.57) | 3,123.54 (5,068.66) |
| In-hospital mortality, % (95% CI)c | 15.2 (14.9–15.4) | 16.8 (16.5–17.1) | 8.0 (6.1–9.9) | 18.6 (18.0–19.2) | 5.0 (4.3–5.7) |
n represents the number of adults hospitalized for ARI between 2018 and 2023 who were admitted to the ICU. aIf start and end dates were the same, a zero-day duration was assigned. bCosts for the population hospitalized with an ARI ICD-10 diagnosis. Costs were not attainable for 30,244 (18.4%) of English trusts hospitalizations and 34,898 (24.2%) of NHSGGC hospitalizations due to insufficient data. Unit costs were extracted from the NHS secondary care tariff for HRGs, with costs for all years based on the HRG4+ 2022/23 National Costs Grouper. Where HRG codes have no nationally agreed tariff, individual patient level data were requested. The median value from the provided individual patient level data were applied as the cost per patient. cIf only year (or year and month) of death was provided and their last recorded date in other medical records was in the same timeframe, that recorded date was adopted as the individual’s date of death. If there was no medical record in the reported year of death, the midpoint of the year (1st July) was assumed as the individual’s date of death. If only death year and death month were provided, the individual was assumed to have died at the approximate midpoint (15th) of the recorded month. Where only the year of death was provided prior to other recorded years in the medical records, the data were omitted from the analysis as implausible. ARI, acute respiratory infection; CI, confidence interval; COVID-19, coronavirus disease 2019; HCRU, healthcare resource utilization; HRG: healthcare resource group; ICD-10, International Classification of Diseases 10th Revision; ICU, intensive care unit; IQR, interquartile range; NHSGGC, National Health Service Greater Glasgow and Clyde; RSV, respiratory syncytial virus; SD, standard deviation.
HCRU of ARI hospitalizations
ARI hospitalization LoS
In both English trusts and NHSGGC, ARI hospitalization median LoS was 4 d (IQR: 1–12 d, 1–11 d, respectively [Table 3]). Among the pathogen-tested hospitalizations, median LoS was 6 d in both English trusts (2–14 d) and NHSGGC (2–15 d). In English trusts, RSV-positive hospitalizations lasted for 5 d (2–12 d), COVID-19-positive hospitalizations for 8 d (3–18 d) and influenza-positive hospitalizations for 4 d (1–10 d). Similarly, in NHSGGC, RSV-positive individuals were hospitalized for 6 d (2–12 d), COVID-19-positive for 10 d (3–27 d) and influenza-positive for 3 d (1–8 d). In English trusts and NHSGGC, ARI hospitalization LoS increased with age (Table S7).
ICU admittance and LoS
ICU admittance during ARI hospitalization was 4.0% in English trusts (median LoS: 5 d [IQR: 2–12]) and 1.4% in NHSGGC (6 d [2–12]); with 5.2% and 2.1% of patients in ICU having a pathogen test, respectively (Table 3). Of the hospitalizations where the patient was admitted to ICU and tested for RSV, COVID-19, and/or influenza, 5.6% (LoS: 3 d [2–8]) and 3.1% (11 d [5–16]) had an RSV-positive test, 5.6% (7 d [3–16]) and 3.2% (10 d [4–18]) had a COVID-19-positive test, and 3.7% (6 d [2–13]) and 2.4% (6 d [2–13]) had an influenza-positive test in English trusts and NHSGGC, respectively. ICU admittance and LoS decreased with age (Tables S8 and S9).
Mean direct medical costs of ARI hospitalization
Over the observational period, mean direct medical cost per ARI ICD-10-diagnosed hospitalization was £3,991.78 (SD: £4,393.73) and £3,596.56 (SD: £6,068.43) in English trusts and NHSGGC, respectively (Table 3); no notable differences were observed across annual cycles (Table S10). In English trusts, RSV-positive hospitalizations cost (£3,843.51 [£3,500.24]) per admission were comparable to the COVID-19-positive (£3,842.30 [£4,699.84]) and influenza-positive (£3,473.90 [£3,640.44]) cohorts. In NHSGGC, costs per RSV-positive (£3,565.80 [£5,593.54]) and influenza-positive (£3,123.54 [£5,068.66]) hospitalization were comparable. COVID-19-positive hospitalizations incurred higher and more variable direct medical costs, at £4,758.00 (£10,512.57) per hospitalization.
Direct medical cost per hospitalization, overall and by sub-cohorts, increased with age. In English trusts, costs among the 18−49 versus ≥90 y groups were £2,980.62 (SD: £4.407.96) versus £5,006.21 (£3,918.17) for RSV-positive hospitalizations; £2,606.01 (5,203.11) versus £4,635.67 (£3,692.50) for COVID-19-positive hospitalizations; and £1,754.91 (£2,445.66) versus £4,619.44 (£3,140.53) for influenza-positive hospitalizations. Similar trends were observed for NHSGGC. Costs were highest among hospitalizations with both lower and upper respiratory tract disease (L/URTD) in English trusts, whilst costs were highest in hospitalizations with LRTD alone in NHSGGC (Table S10).
Microbiology-confirmed RSV versus ICD-10 coding for diagnosis
Between 2018/19 and 2022/23, only 63.5% and 33.7% of microbiology-confirmed RSV-positive hospitalizations had an accompanying RSV-specific ICD-10 diagnosis code in English trusts and NHSGGC, respectively. In English trusts, this proportion was evenly distributed across age and risk groups, whilst in NHSGGC, proportions increased with age (Table S11). Of the hospitalizations with an RSV ICD-10 diagnosis code, 68.6% and 89.1% had an accompanying microbiology-confirmed RSV-positive test in English trusts and NHSGGC, respectively, with proportions increasing slightly with age.
Discussion
This study investigated the population characteristics, incidence risk, and economic burden of ARI-hospitalized adults ≥18 YOA from 2018/19 to 2022/23 in English and Scottish secondary care settings. Findings highlight the comparable burden of RSV-positive hospitalizations to COVID-19- and influenza-positive hospitalizations across both regions, underscoring the importance of effective vaccination strategies to reduce RSV’s burden.6,14 Importantly, these findings provide a pre-vaccine baseline against which the impact of the UK RSV adult vaccination rollout in 2024/25 for those aged 75–79 y can be interpreted. Early post-rollout evaluations reported approximately 30% reductions in hospitalizations, which is consistent with our observation that RSV hospitalization burden in adults, particularly older adults and those with comorbidities, is considerable and, therefore, amenable to meaningful reduction through vaccination.24,25
Incidence risk of first ARI-related hospitalization increased with age in both English trusts and NSHGGC. This aligns with Symes et al., who assessed RSV-ARI hospitalization among those aged ≥65 y in England and reported incidence rising from 30.9 per 100,000 individuals among those aged 65–74 y to 107.9 per 100,000 individuals among those aged ≥80 y.26 In the present analysis, although incidence was highest in the oldest age group, rates increased across successive age bands, indicating a progressive rise in ARI risk throughout older age rather than a concentration only among the oldest. This suggests that limiting RSV vaccination to those aged ≥75 y may overlook a substantial preventable burden in lower age bands.
Annual incidence risk of first ARI-related hospitalization increased from 2020/21 to 2022/23 in English trusts and NHSGGC. This pattern likely reflects a combination of true increases in respiratory virus transmission after relaxation of COVID-19 public health measures (with renewed circulation of multiple pathogens) and ascertainment effects related to changes in care pathways and diagnostics. In particular, the 2020/21 season coincided with periods of reduced circulation of non-COVID-19 respiratory viruses, whereas subsequent seasons were likely characterized by more typical respiratory virus activity following easing of restrictions.27 In parallel, there was likely heightened clinical awareness of respiratory infections and greater use of viral testing and multiplex polymerase chain reaction (PCR) panels among patients presenting with ARI symptoms compared with earlier years, which could increase the likelihood that an admission is coded and captured as ARI-related, independent of any underlying change in severity. A similar spike to that seen in the present analysis was observed in UK surveillance data between 2021 and 2023 following relaxation of COVID-19 public health measures, and increased pathogen testing among patients with ARI symptoms after the COVID-19 pandemic.28,29 Of the three pathogens in this study, RSV was the least frequently tested, accounting for only 13.3% and 26.2% of pathogen-tested ARI-related hospitalizations in English trusts and NHSGGC, respectively.
RSV-positive ARI-related hospitalizations had higher proportions of older adults and adults with comorbidities versus the pathogen-tested and COVID-19- and influenza-positive sub-cohorts, supporting evidence that these populations may have a higher risk of hospitalization following RSV infection.26,30 Of the older adult risk groups examined, there was a higher proportion of RSV-positive ARI-related hospitalizations among high-risk individuals versus non-high-risk individuals in both settings. While these observations could be attributed to different testing practices for each pathogen, literature has similarly reported that older age and comorbidities are significant factors for severe RSV infections, translating to secondary care presentation.31 ICU admissions decreased with age, whilst mortality increased. In line with our study, a UK analysis on ICU intensivist admission decisions reported that older or frail adults may generally be less likely to be admitted to ICU.32 A 2025 report from the European Respiratory Virus Surveillance Summary (ERVISS) similarly revealed that although RSV-related ICU admissions among those ≥60 YOA were low, mortality rates were high.33 Median RSV ICU LoS was shorter in English trusts than in NHSGGC (3 and 11 d, respectively), although IQR’s overlapped. This difference could be attributed to between-setting differences in clinical practice and recording, rather than a true difference in disease course. Limited data on RSV-associated ARI-hospitalized ICU LoS in England and Scotland among older adults are currently available for comparisons to be made.
There is limited-to-no literature exploring the healthcare and economic burden of RSV in the UK. In this study, the economic burden per RSV-positive hospitalization was comparable to influenza- and COVID-19-positive hospitalizations in English trusts, and to influenza-positive hospitalization in NHSGGC. Due to lower RSV testing compared with the other pathogens, and the extent of under-reporting RSV, total economic burden may be underestimated. However, as pathogen testing may be prioritized for patients presenting with significant symptoms, and, therefore, more severe disease, the potential for per-case cost overestimation must also be acknowledged. Direct NHS costs of ARI-related hospitalization generally increased with age. This was expected owing to established higher rates of multimorbidity among older adults, with the UK Health Security Agency reporting increasing hospital and community health service costs with age.34,35
Two-thirds of RSV-positive hospitalizations in NHSGGC did not have an accompanying RSV-specific ICD-10 code, compared with one-third of hospitalizations in English trusts, suggesting potential limitations of using ICD-10 codes to estimate RSV burden. Under-reporting can occur when RSV-positive spells are linked to generic ICD-10 codes and variations in RSV-test sensitivity.18,36 In practice, RSV may be missed in routine discharge coding if the summary focuses on a nonspecific ARI diagnosis, such as ARI itself or pneumonia, or if the RSV test result is not clearly documented or not available at the time of coding. These issues, alongside imperfect test sensitivity, are consistent with evidence that RSV under-ascertainment can be substantial and may be reduced by optimizing sampling/testing approaches. Indeed, studies exploring under-ascertainment of RSV suggested that RSV detection increased when using additional specimen versus nasopharyngeal swabs alone, requiring a ≥2-fold correction factor. A similar level of RSV under-reporting to that observed in our study was also reported in Denmark between 2015 and 2018, where only 58% of adults hospitalized with a positive RSV test received an ICD-10 RSV-specific diagnosis.37 A similar study in the Netherlands reported that the number of microbiology-confirmed RSV-positive hospitalizations was 5.6 times higher than the number of hospitalizations with an RSV-specific ICD-10 code.38
A recently published study by Public Health Scotland highlighted the crucial role of RSV vaccination in broader seasonal immunization programs.39 By improving access to RSV vaccines, RSV burden may be significantly reduced. Additionally, our study contributes to the growing body of evidence that RSV hospitalizations are notably higher among those ≥50 YOA and with comorbidities, supporting broadening current UK RSV vaccination recommendations to include younger at-risk populations. Expanding recommendations should be paired with continuous surveillance of RSV to track health outcomes and vaccine uptake, such as expanded RSV testing protocols or routine linkage of microbiology data and administrative records, aligning with the call of the UK Joint Committee on Vaccination and Immunization (JCVI) for improved surveillance to monitor the impact of RSV vaccination programs.4
This study has several limitations. By using EHR data, this study is subject to the typical limitations associated with real-world data. Consequently, the healthcare and economic burden may be underestimated for two reasons. First, ARI- and comorbidity-related diagnoses were solely identified using ICD-10 codes, meaning some cases may not have been captured and, second, NHS national tariffs and HRG codes do not capture the complete cost of treating a patient (excluded costs for high-cost drugs, rehabilitation centers, laboratory tests, outpatient, or emergency room attendances). In addition, as costs were based on HRG4+ 2022/23 tariffs, inflation and changes in treatment costs during the study period were not accounted for. Further research could also account for patient-level cost drivers, such as specific complications or long-term sequelae, to improve the precision of burden estimates beyond HRG tariffs. The four English trusts and NHSGGC catchment populations represented 3.5% and 21.7% of the adult populations of England and Scotland, respectively, and, therefore, may not be fully representative of the entire national adult population, potentially limiting the generalizability of the absolute incidence risks to the entire UK population. Nevertheless, age, ethnicity, sex, and socioeconomic status distributions closely resembled the national distribution, supporting the use of these data as a reasonable basis for estimating RSV burden in the absence of a national linked database.21,22,40–42 Due to small subgroup numbers, it was not possible to investigate multi-pathogen infections without needing to censor a large number of results. It may be of interest to investigate whether outcomes differ for single- and multi-pathogen infections in future work. Microbiology confirmation is subject to clinician testing behavior. Whilst the majority of tests were multiplex PCR panels and hence tested for all ARIs, some testing may have been clinician-driven and based on clinical presentation, severity, age, comorbidity profile, and infection control considerations. Therefore, the tested population may be enriched for patients with more severe illness or higher clinical risk compared with the full population of RSV-associated admissions. Additionally, the imputation of in-hospital mortality dates may impact the mortality rate. In particular, if only year of death was provided and a patient died during the last month of a calendar year, with an ARI hospitalization being the last recorded date earlier in the calendar year, the mortality rate may be overestimated. However, RSV and influenza in-hospital mortality rates in the present study were lower than 30-d mortality rates published in the literature.26 Finally, the RSV cohort was unvaccinated whilst the COVID-19 and influenza cohorts would have included an undetermined proportion of vaccinated individuals, due to many vaccines for respiratory illnesses being delivered within the community or in primary care. This potentially introduces heterogeneity and confounds comparisons as vaccination has the potential to reduce disease severity and thus, HCRU.
Conclusion
In conclusion, a comprehensive analysis of routine data for RSV burden in English and Scottish secondary care settings between 2018 and 2023 is provided, highlighting that RSV hospitalization imparts a burden comparable to influenza and COVID-19 hospitalization per case. Furthermore, RSV burden is likely underestimated in the UK, due to inconsistent RSV testing and diagnosis. These findings support the need for improved surveillance and for broadened vaccination recommendations in order to manage, monitor, and reduce the substantial healthcare burden of RSV among adults.
Supplementary Material
Acknowledgments
The authors acknowledge Costello Medical for editorial assistance and publication coordination, on behalf of GSK, and acknowledge May-Li MacKinnon, Costello Medical, UK, for medical writing and editorial assistance based on authors’ input and direction. An anonymized dataset for this study was provided by the West of Scotland Safe Haven research database service at NHS Greater Glasgow and Clyde under REC approval 22/WS/0163. We believe using patient data is vital to improve health and care for everyone and would, thus, like to thank all those involved for their contribution.
Substantial contributions to study conception and design: RMR, SL, TP, DR, AP, JW, and EP; substantial contributions to analysis and interpretation of the data: RMR, SL, TP, EP, DR, AP, JW, LC, ET, and AM; drafting the article or revising it critically for important intellectual content: RMR, SL, TP, EP, DR, AP, JW, LC, ET, and AM; final approval of the version of the article to be published: RMR, SL, TP, EP, DR, AP, JW, LC ET, and AM.
Biography
Rachel M. Reeves is a Director, Global Real-World Evidence & Health Outcomes Research Scientist, RSV at GSK and holds a PhD in Epidemiology from University College London.
Funding Statement
This work was supported by GlaxoSmithKline (Study identifier: VEO-000619). Support for third-party writing assistance for this article, provided by May-Li MacKinnon, Costello Medical, United Kingdom, was funded by GlaxoSmithKline in accordance with Good Publication Practice (GPP 2022) guidelines (https://www.ismpp.org/gpp-2022).
Disclosure statement
RMR, EP, ET, and AM: are employees of, and hold financial equities, in GSK; TP: is a contingent worker at GSK and received consulting fees from BioNTech and UCB, and from Pathfinder, John Snow Inc, and UNAIDS through Impact Epilysis. The author declares contracts with BioNTech and UCB, and with Pathfinder, John Snow Inc, and UNAIDS through Impact Epilysis; SL, AP, DR, and JW: employees of Arcturis, which received payments from GSK; LC: is an employee of Arcturis, which received payments from GSK; received personal consultancy fees from Pfizer; participated as a member for the safety monitoring board for the George Institute for Global Health.
Data sharing statement
Data used for this publication were curated and analyzed by Arcturis Data. For any queries related to accessing the anonymized subject level data, please contact Arcturis Data.
Supplementary material
Supplemental data for this article can be accessed online at https://doi.org/10.1080/21645515.2026.2675075
References
- 1.Nguyen-Van-Tam JS, O’Leary M, Martin ET, Heijnen E, Callendret B, Fleischhackl R, Comeaux C, Tran TMP, Weber K.. Burden of respiratory syncytial virus infection in older and high-risk adults: a systematic review and meta-analysis of the evidence from developed countries. Eur Respi Rev. 2022;31(166):220105. doi: 10.1183/16000617.0105-2022. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Shi T, Denouel A, Tietjen AK, Campbell I, Moran E, Li X, Campbell H, Demont C, Nyawanda BO, Chu HY, et al. Global disease burden estimates of respiratory syncytial virus-associated acute respiratory infection in older adults in 2015: a systematic review and meta-analysis. J Infect Dis. 2020;222(Suppl 7):S577–S583. [DOI] [PubMed] [Google Scholar]
- 3.Savic M, Penders Y, Shi T, Branche A, Pirçon JY. Respiratory syncytial virus disease burden in adults aged 60 years and older in high-income countries: a systematic literature review and meta-analysis. Influenza Other Respir Viruses. 2023;17(1):e13031. doi: 10.1111/irv.13031. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Department of Health and Social Care . Respiratory syncytial virus (RSV) immunisation programme for infants and older adults. 2023. https://www.gov.uk/government/publications/rsv-immunisation-programme-jcvi-advice-7-june-2023/respiratory-syncytial-virus-rsv-immunisation-programme-for-infants-and-older-adults-jcvi-full-statement-11-september-2023.
- 5.Kriger O, Gefen-Halevi S, Leshem E, Smollan G, Belausov N, Egbarye A, Khashab R, Odeh M, Saffia A, Barak Y, et al. Viral co-pathogens in COVID-19 acute respiratory syndrome – what did we learn from the first year of pandemic? Int J Infect Dis. 2022;116(226):226–15. doi: 10.1016/j.ijid.2022.01.018. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Meier GC, Watkins J, McEwan P, Pockett RD. Resource use and direct medical costs of acute respiratory illness in the UK based on linked primary and secondary care records from 2001 to 2009. PLOS ONE. 2020;15(8):e0236472. doi: 10.1371/journal.pone.0236472. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Piralla A, Chen Z, Zaraket H. An update on respiratory syncytial virus. BMC Infect Dis. 2023;23(1):734. doi: 10.1186/s12879-023-08730-x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Zhang T, Reeves RM, Ma S, Miao Y, Sun S, Orrico-Sánchez A, Panning M, Urchueguía-Fornes A, Vuichard-Gysin D, Nair H, et al. Estimating the respiratory syncytial virus-associated hospitalisation burden in older adults in European countries: a systematic analysis. BMC Med. 2025;23(1):453. doi: 10.1186/s12916-025-04249-x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Moderna News . Moderna receives Medicines and Healthcare products Regulatory Agency marketing authorization in the UK for RSV vaccine. 2025. https://investors.modernatx.com/news/news-details/2025/Moderna-Receives-Medicines-and-Healthcare-Products-Regulatory-Agency-Marketing-Authorization-in-the-UK-for-RSV-Vaccine/default.aspx.
- 10.PULSE today . UK approves first RSV vaccine for pregnant women and older adults. 2023. https://www.pulsetoday.co.uk/news/clinical-areas/respiratory/uk-approves-first-rsv-vaccine-for-both-infants-and-older-adults/.
- 11.GSK . Medicines and Healthcare products Regulatory Agency authorises GSK’s Arexvy, the first respiratory syncytial virus (RSV) vaccine for older adults. 2023. https://www.gsk.com/en-gb/media/press-releases/medicines-and-healthcare-products-regulatory-agency-authorises-gsk-s-arexvy-the-first-respiratory-syncytial-virus-rsv-vaccine-for-older-adults/.
- 12.UK Health Security Agency . Your guide to the RSV vaccine for older adults. 2026. https://www.gov.uk/government/publications/respiratory-syncytial-virus-rsv-vaccination-for-older-adults/your-guide-to-the-rsv-vaccine-for-older-adults.
- 13.Wilkinson T, Beaver S, Macartney M, McArthur E, Yadav V, Lied-Lied A. Burden of respiratory syncytial virus in adults in the United Kingdom: a systematic literature review and gap analysis. Influenza Other Respir Viruses. 2023;17(9):e13188. doi: 10.1111/irv.13188. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Fleming DM, Taylor RJ, Lustig RL, Schuck-Paim C, Haguinet F, Webb DJ, Logie J, Matias G, Taylor S. Modelling estimates of the burden of respiratory syncytial virus infection in adults and the elderly in the United Kingdom. BMC Infect Dis. 2015;15(1):443. doi: 10.1186/s12879-015-1218-z. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Clausen C, Egeskov-Cavling AM, Hayder N, Sejdic A, Roed C, Holler JG, Nielsen L, Eiberg MF, Rezahosseini O, Østergaard C, et al. Clinical manifestations and outcomes in adults hospitalized with respiratory syncytial virus and influenza A/B: a multicenter observational cohort study. Open Forum Infect Dis. 2024;11(10):ofae513. doi: 10.1093/ofid/ofae513. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Korsten K, Adriaenssens N, Coenen S, Butler CC, Verheij TJM, Bont LJ, Wildenbeest JG, Korsten K, Adriaenssens N, Coenen S, et al. World Health Organization influenza-like illness underestimates the burden of respiratory syncytial virus infection in community-dwelling older adults. J Infect Dis. 2022;226(Supplement_1):S71–S78. doi: 10.1093/infdis/jiab452. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.McLaughlin JM, Khan F, Begier E, Swerdlow DL, Jodar L, Falsey AR. Rates of medically attended RSV among US adults: a systematic review and meta-analysis. Open Forum Infect Dis. 2022;9(7):ofac300. doi: 10.1093/ofid/ofac300. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Onwuchekwa C, Moreo LM, Menon S, Machado B, Curcio D, Kalina W, Atwell JE, Gessner BD, Siapka M, Agarwal N, et al. Underascertainment of respiratory syncytial virus infection in adults due to diagnostic testing limitations: a systematic literature review and meta-analysis. J Infect Dis. 2023;228(2):173–184. doi: 10.1093/infdis/jiad012. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.UK Health Security Agency . Public health microbiology division: virus reference department (VRD) user manual. 2025. https://www.gov.uk/government/publications/virus-reference-department-vrd-user-manual.
- 20.Papi A, Ison Michael G, Langley Joanne M, Lee D-G, Leroux-Roels I, Martinon-Torres F, Schwarz TF, van Zyl-Smit RN, Campora L, Dezutter N, et al. Respiratory syncytial virus prefusion F protein vaccine in older adults. N Engl J Med. 2023;388(7):595–608. doi: 10.1056/NEJMoa2209604. [DOI] [PubMed] [Google Scholar]
- 21.Office for Health Improvement and Disparities . Trust catchment summary. NHS Acute (Hospital) Trust Catchment Populations; 2022. https://app.powerbi.com/view?r=eyJrIjoiODZmNGQ0YzItZDAwZi00MzFiLWE4NzAtMzVmNTUwMThmMTVlIiwidCI6ImVlNGUxNDk5LTRhMzUtNGIyZS1hZDQ3LTVmM2NmOWRlODY2NiIsImMiOjh9. [Google Scholar]
- 22.National Records of Scotland . Rounded population estimates – data. Scotland’s Census; 2022. https://www.scotlandscensus.gov.uk/documents/scotland-s-census-2022-rounded-population-estimates-quality-assurance-information/. [Google Scholar]
- 23.NHS Digital . HRG4+ 2022/23 national costs grouper. 2023. https://digital.nhs.uk/services/national-casemix-office/downloads-groupers-and-tools/hrg4-2022-23-national-costs-grouper.
- 24.UK Health Security Agency . The UK’s first RSV vaccination programme protects older people. 2025. https://www.gov.uk/government/news/uks-first-rsv-vaccination-programme-protects-older-people.
- 25.Mensah AA, Whitaker H, Andrews NJ, Watson CH. Early impact of RSV vaccination in older adults in England. Lancet. 2025;405(10485):1139–1140. doi: 10.1016/S0140-6736(25)00346-0. [DOI] [PubMed] [Google Scholar]
- 26.Symes R, Keddie SH, Walker J, McKeever T, Ahmad S, Arnold D, Evans CM, Pelosi E, Rahman NM, Sapey E, et al. Burden of respiratory syncytial virus infection in older adults hospitalised in England during 2023/24. J Infect. 2025;91(3):106570. doi: 10.1016/j.jinf.2025.106570. [DOI] [PubMed] [Google Scholar]
- 27.Koltai M, Krauer F, Hodgson D, van Leeuwen E, Treskova-Schwarzbach M, Jit M, Flasche S. Determinants of RSV epidemiology following suppression through pandemic contact restrictions. Epidemics. 2022;40:100614. doi: 10.1016/j.epidem.2022.100614. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28.Leung K, Wu JT, Leung GM. Effects of adjusting public health, travel, and social measures during the roll-out of COVID-19 vaccination: a modelling study. Lancet Public Health. 2021;6(9):e674–e682. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.UK Health Security Agency . Surveillance of influenza and other seasonal respiratory viruses in the UK, winter 2022 to 2023. 2026. https://www.gov.uk/government/statistics/annual-flu-reports/surveillance-of-influenza-and-other-seasonal-respiratory-viruses-in-the-uk-winter-2022-to-2023#conclusions.
- 30.Mensah AM, Whitaker H, Andrews NJ, Watson CH. Early impact of RSV vaccination in older adults in England. Lancet. 2025;405(10485):1139–1140. [DOI] [PubMed] [Google Scholar]
- 31.Alfano F, Bigoni T, Caggiano FP, Papi A-O. Respiratory syncytial virus infection in older adults: an update. Drugs Aging. 2024;41(6):487–505. doi: 10.1007/s40266-024-01118-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 32.Bassford CR, Krucien N, Ryan M, Griffiths FE, Svantesson M, Fritz Z, Perkins GD, Quinton S, Slowther A-M. U.K. intensivists’ preferences for patient admission to ICU: evidence from a choice experiment. Crit Care Med. 2019;47(11):1522–1530. doi: 10.1097/CCM.0000000000003903. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 33.ERVISS . Overview of respiratory virus epidemiology in the EU/EEA, week 20. 2025. https://erviss.org/.
- 34.UK Health Security Agency . Ageing and health expenditure. 2019. https://ukhsa.blog.gov.uk/2019/01/29/ageing-and-health-expenditure/.
- 35.Soley-Bori M, Ashworth M, Bisquera A, Dodhia H, Lynch R, Wang Y, Fox-Rushby J. Impact of multimorbidity on healthcare costs and utilisation: a systematic review of the UK literature. Br J Gen Pract. 2021;71(702):e39–e46. doi: 10.3399/bjgp20X713897. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 36.Anderson E, Tippett A, Begier E, Gibson T, Ess G, Patel V, Taylor M, Reese O, Salazar L, Jadhao S, et al. Relative contribution of diagnostic testing to the diagnosis of respiratory syncytial virus in hospitalized adults in the United States. J Infect Dis. 2024;230(6):1342–1351. doi: 10.1093/infdis/jiae346. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 37.Egeskov-Cavling A-O, Johannesen CK, Lindegaard B, Fischer TK, Nair H, Campbell H, Nohynek H, Teirlinck A, Bont L, Openshaw P, et al. Underreporting and misclassification of respiratory syncytial virus-coded hospitalization among adults in Denmark between 2015–2016 and 2017–2018. J Infect Dis. 2024;229(Supplement_1):S78–S83. doi: 10.1093/infdis/jiad415. [DOI] [PubMed] [Google Scholar]
- 38.Pliakas T, Goeijenbier M, Ong DSY, Bruns A, van den Berge M, den Hollander J, Hemels M, Tjhie J, Jaarsma E, Velthove KJ, et al. Burden of disease (BoD), healthcare resource use (HCRU) and costs of respiratory syncytial virus (RSV) among adults in the Netherlands in 2021–2023: a real-world retrospective observational study of five hospitals. Paper presented at: ESCMID 2025; Vienna, Austria; 2025. Apr 11–15. [Google Scholar]
- 39.Hameed SS, Robertson C, Morrison K, McQueenie R, McMenamin J, Ghebrehewet S, Marsh K. Early evidence of RSV vaccination impact on hospitalisation rates of older people in Scotland. Lancet Infect Dis. 2025;25(3):256–258. doi: 10.1016/S1473-3099(25)00064-7. [DOI] [PubMed] [Google Scholar]
- 40.Office for National Statistics . Male and female populations. 2023. https://www.ethnicity-facts-figures.service.gov.uk/uk-population-by-ethnicity/demographics/male-and-female-populations/latest/.
- 41.Office for National Statistics . Ethnic group, England and Wales: census. 2021. https://www.ons.gov.uk/peoplepopulationandcommunity/culturalidentity/ethnicity/bulletins/ethnicgroupenglandandwales/census2021.
- 42.Office for National Statistics . Age groups. 2023. https://www.ethnicity-facts-figures.service.gov.uk/uk-population-by-ethnicity/demographics/age-groups/latest/.
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.