Table 1.
Study characteristics of included studies for travellers, ICP and HCW.
| Study | Study Design | Enrolment Period | Enrolment Site | Sample Size | Study Population | Theoretical Framework | Outcome Measures * | Vaccination Coverage | Quality Score ** |
|---|---|---|---|---|---|---|---|---|---|
| Balaban, 2013 [16] | Pre- and post-travel surveys | 2009 | USA | 186 | American Hajj pilgrims | None | Seasonal influenza | - | Low |
| Barasheed, 2014 [17] | Cross-sectional survey | 2011–2012 | Mina (Mecca) | 966 | Australian Hajj pilgrims | None | Influenza | 62% | High |
| Duffy, 2013 [18] | Cross-sectional survey | 2007 (Aug.–Sept.) | United States | 1691 | American travellers to Asia | None | JE | 11% | Medium |
| Frew, 2017 [19] | Cross-sectional survey | 2015 (Feb.–March) | Ferry ports of 2 popular islands, Thailand | 1680 | Backpackers from Europe, Canada, Australia and New-Zealand (94%) | None (KAP) | HBV | 31% completed series | High |
| Goodman, 2014 [20] | Online cross-sectional survey | 2010 (Feb.) | UK | 302 | Travellers to the meningitis belt of Africa in last 3 years or planned to do so next 6 months | None | MenAWCY | 30% | Medium |
| Herbinger, 2011 [21] | Online cross-sectional survey | 2009 (Dec.) | Netherlands, Czech Republic, Spain, Sweden | 4203 | Travellers to countries of moderate or high prevalence for HBV in the last 5 years | None | HBV | 39% in the previous 5 years | Medium |
| Heywood, 2016 [22] | Online cross-sectional survey | 2014 (Aug.–Oct.) | Australia, Finland, Germany, Norway, Sweden, UK, Canada | 27,386 | Travellers (18–65 years) who travelled to HAV endemic countries in Africa, Asia, South/Central America in the last 3 years | None | HAV/HBV | 27% for 3-dose combined HAV and HBV and 37% for 2-dose monovalent HAV schedules | Medium |
| Igreja, 2019 [23] | Cross-sectional survey | 2019 (May–June) | Travel Clinic, Lisbon, Portugal | 55 | Portuguese travellers | None | Attitudes to vaccinations in general | - | Low |
| Lammert, 2016 [24] | Retrospective study | 2012–2014 | clinics from Global TravEpiNet, USA | 24,478 | International travellers who sought pre-travel health advice | None | Refusal rates of recommended vaccines and reasons | 25% refused one or more recommended vaccine(s) | High |
| Paudel, 2017 [25] | Prospective enhanced surveillance study | 2013 (Feb–2014 (Jan.) | Australia | 180 | confirmed cases of typhoid, paratyphoid, measles, HAV, HEV, chikungunya, malaria | None | Seeking pre-travel advice and uptake | 25% sought pre-travel advice and 16% got vaccinated | Medium |
| Pavli, 2019 [26] | Cross-sectional survey by email | 2015 (Nov.)–2016 (Mar.) | Greece | 231 | Greek (non-healthcare) students from 36 universities, planning to study abroad | None | Men, intention to vaccinate | 23% vaccinated, 15% intention | Medium |
| Pfeil, 2010 [27] | 2 cross-sectional surveys | 2009 (Jan.–Feb.), 2010 (Jan.) | Centre for Travel Health, Zurich, Switzerland | 623 | Travellers to a resource-limited destination | None (KAP) | Seasonal (and pandemic) influenza | 14% seasonal influenza | High |
| Selcuk, 2016 [28] | Cross-sectional survey | 2013 (July) | Istanbul Ataturk Airport, Istanbul, Turkey | 124 | Turkish travellers to Africa | None | Recommended for destination | 53% vaccinated pre-travel | Medium |
| Tan, 2017 [29] | Retrospective cohort study | 2012 (Jan.)–2013 (Dec.) | Mayo Clinic Travel and Tropical Medicine Clinic, Minnesota, USA | 2073 | Children and adults who sought pre-travel advice (19% VFR) | None | Documented receipt or positive serology or completion of series | 94% men in VFR, 12% rabies in VFR | High |
| Tashani, 2016 [30] | Cross-sectional survey | 2014–2015 | Immunization clinic, Sydney, Australia | 300 | Travellers (>18 year) planning to attend Hajj | None | Pneu and DTP when recommended | 17% pneu, 14% DTP | Medium |
| Wiemken, 2015 [31] | Cross-sectional study | 2013 (Nov.)–2014 (July) | University of Louisville, Travel Clinic, USA | 183 | American travellers before their consultation | TPB | Intention to get vaccinated | Not given | High |
| Yanni, 2010 [32] | Pre- and post-travel surveys | 2008 (June–Sept.) | Departure lounges at airports in New York, Chicago, Los Angeles, and San Francisco | 1301 (pre) (337 post) | American travellers who will travel to Asia | KAP | Influenza | 41% | High |
| Akin, 2016 [33] | Cross-sectional survey | 2015 (July–Sep.) | Daycare chemotherapy unit of Hacettepe University Cancer Institute, Ankara, Turkey | 229 | Adult patients with cancer receiving chemotherapy | None | Adult vaccination coverage (influenza, tetanus, hepatitis, pneu) | 54% were vaccinated at least once, only 9% after cancer diagnosis | Medium |
| Althoff, 2010 [34] | Nested influenza study (interview administered surveys) | 2006–2007 and 2007–2008 | 5 cities in the USA | 1462 | HIV+ women | HBM | Influenza | 55–57% of women reported vaccination (about 44% not vaccinated) | Medium |
| Battistella, 2019 [35] | Cross-sectional observational study | 2017 (Jan.–July) | 7 large dialysis services, Italy | 703 | Dialysis patients | None | Influenza | 58% adherence | High |
| Chehab, 2018 [36] | Cross-sectional study (in longitudinal cohort) | 2012 (Nov.)–2013 (Oct.) | Germany | 579 | SLE patients (48% on IS) | None | Influenza, tetanus, pneu, men and previous refusal | 45% influenza (last year); 65% tetanus; 32% pneu; 6% men | High |
| Chin-Yee, 2011 [37] | Cohort study (one time follow-up) | 2009 (Oct.)–2010 (Mar.) | Tertiary care cancer center, Canada | 129 | Patients with hematologic malignancies (92% chemotherapy, 76% in past 3 mo) | None | Seasonal influenza (and pandemic) | 57% seasonal influenza | Medium |
| Gagneux-Brunon, 2019 [38] | Cross-sectional survey | Unknown | France | 468 | HIV+ patients | None | Pneu, HAV, HBV, seasonal influenza | 30% IPD; 24% HAV; 64% HBV; 40% influenza | Low |
| Haroon, 2011 [39] | Cross-sectional survey (audit) | 2009 (Sept.) | Outpatient clinics, tertiary university hospital, Ireland | 110 | Rheumatology patients on IS | None | Seasonal influenza and pneu | 34% influenza; 11% pneu; 11% both | Medium |
| Harrison, 2017 [40] | Cross-sectional survey | 2015 (Aug.–June) | HIV out-patient department of the University Hospital of Vienna, Austria | 455 | HIV patients | None | Seasonal influenza | 12% influenza | Medium |
| Harrison, 2018 [41] | Cross-sectional survey | 2017 (July–Oct.) | Outpatient clinic, Medical University of Vienna, Austria | 490 | Inflammatory rheumatic disease patients on IS | None | Seasonal influenza | 25% influenza | Medium |
| Lachenal, 2010 [42] | Cross-sectional survey (standardized questionnaire) | 2008 (Jan.) | Centre Léon-Bérard, Lyon, France | 200 | Patients with haematological malignancies (hospitalized or at outpatient clinic) | None | Influenza | 26% | Medium |
| Loubet, 2015 [43] | Self-reported cross-sectional survey | 2013 (Summer) | AVNIR, a group of associations whose goal is to support ICP, France | 3653 | 79% autoimmune, 13% SOT, 8% treated for hematological malignancies. 85% on IS. | KAP | Influenza and pneu | 59% seasonal influenza and 49% pneu | Medium |
| Loubet, 2018 [44] | Self-reported cross-sectional survey | 2015 (Dec.)–2016 (March) | AFA, national association of patients with IBD, France | 199 | IBD patients (62% receiving IS) | KAP | Influenza and pneu | 34% influenza, 38% pneu | Medium |
| Malhi, 2015 [45] | Cross-sectional survey (self-reported, paper-based) | 2013 (Sept)–2014 (Jan.) | IBD Clinic or Endoscopy Suite at Mount Sinai Hospital, Toronto, Canada | 305 | IBD patients (53% using biologicals/steroids) | None | Influenza, pneu, HAV, HBV, VZV, men, HVZ, HPV | 61% influenza, 10% pneu, 61% HBV, 52% HAV, 26% VZV, 21% men, 5% HZV, 11% HPV | High |
| Miller, 2018 [46] | Cross-sectional survey | 2016 (June–Sept.) | 3 tertiary autologous and allogeneic HSCT centres, UK | 93 | HSCT patients (79% autologous) | adjusted HBM | Intention to receive seasonal influenza | 76% expressed high intent | High |
| Mouthon, 2010 [47] | Cross-sectional survey (standardized questionnaires) | 2006 and 2007 | Dept. Of Internal Medicine, Cochin Hospital, France | 177 | Patients with systemic sclerosis | None | Influenza | 39% (last year) | Medium |
| Narula, 2012 [48] | Cross-sectional survey | 2010 (May–Aug.) | McMaster University Medical Centre Digestive Disease Clinic, Canada | 250 | IBD patients (63% on IS) | None | Seasonal (and H1N1) influenza | 25% seasonal influenza | High |
| Nguyen, 2017 [49] | Cross-sectional survey with invitation RCT for new pneu vaccine) | 2014 (Oct.–Nov.) | Outpatients clinic of rheumatology at 2 hospitals in Graasten, Denmark | 192 | RA patients | None | Influenza and pneu | 59% seasonal influenza ever, 49% last year, 6% pneu | High |
| Poeppl, 2015 [50] | Cross-sectional survey | 2013 (July)–2013 (Oct.) | Outpatient departments of the General Hospital Vienna, Austria | 444 | Patients with malignancies (55% solid tumours, 22% haematological malignancy, and 17% had no diagnosed malignancy) | None | Influenza | 18% influenza last year | Medium |
| Price, 2019 [51] | Cross-sectional survey | 2014 (June–July) | Cancer center providing ambulatory care, USA | 703 | Patients (83%) (and caregivers and family (17%) of patients) treated for malignancies | None | Influenza | Patients 72%, caregivers 71% (last year) | Medium |
| Restivo, 2017 [52] | Prospective observational study | 2014 (Oct.)–2015 (April) | SOT Reference Center in Palermo, Sicilia, Italy | 82 | SOT recipients during hospital admission for transplantation | None | Influenza | 38% | Medium |
| Ruiz-Cuesta, 2016 [53] | Prospective observational study | 2012 (Jan.–March) | Reina Sofía University Hospital, Córdoba, Spain | 153 | IBD (50% UC, 50% CD) patients (>14 years old), 34% on biologicals/corticosteroids | None | HAV, HBV, VZV, MMR assessed by registry | 84% | Medium |
| Sadlier, 2015 [54] | Retrospective study, with provider-delivered survey | 2014 (Jan.–Feb.) | Tertiary university hospital in Ireland | 170 | Dermatology patients prescribed systemic IS | None | Influenza and pneu | 38% seasonal influenza last year, 21% pneu last 5 years, 18% both. | Medium |
| Sandler, 2016 [55] | Cross-sectional, telephone survey | 2013 (July–Sept.) | Memorial Medical Center in Chicago, USA | 102 | RA patients (85–91% taking IS) | None | Self-reported and EHR influenza, pneu, and HZV | 79% influenza last season, 54% pneu and 8% HZV | High |
| Savage, 2011 [56] | Retrospective audit | 2010 (Aug.–Oct.) | Outpatient dermatology clinics in Aberdeen RoyalInfirmary, Scotland | 87 | Immunocompromised dermatology patients | None | Influenza and pneu | 70% influenza (last year), 22% pneu | Medium |
| Struijk, 2015 [57] | Cross-sectional survey | Unknown | Renal Transplant Unit, Academic Medical Center, Amsterdam, NL | 526 | 77% renal transplant recipients (and their nephrologists) | KAB | Influenza, tetanus, pneumococci, HAV, HBV | 56% influenza, 15–30% tetanus, 0–5% pneu, 5–30% HAV, 10–20% HBV | High |
| Teich, 2011 [58] | Cross-sectional survey | 2009 (April–Sept.) | Germany | 203 | IBD patients who had not received vaccination counseling ≥1 year (54% on IS) | None | Vaccinations in general | 67% tetanus (<10 years), 21% pertussis, 28% seasonal influenza, 9% pneu | High |
| Urun, 2013 [59] | Cross-sectional survey (with face-to-face interviews) | 2012 (Jan.–March) | Medical Oncology Department of Ankara University Faculty of Medicine, Turkey | 359 | Patients with malignancies | None | Influenza and pneu | 17% influenza 4% pneumococcal | Medium |
| Waszczuk, 2018 [60] | Cross-sectional survey (self-completed) | Unknown | Wrowclaw, Poland | 195 | IBD patients (70% on IS) | None | Influenza, HBV and pneu | HBV 55%; Tdap 12%; HAV 7%; annual influenza 6%; VZV/HZV 3%, and pneu 2% | High |
| Wilckens, 2011 [61] | Cross-sectional survey | 2009 (April–Oct.) | IBD outpatients’ clinic, a tertiary referral center, Lueneburg, Germany | 102 | IBD patients (57% CD, 91% on IS) | None | Vaccinations in general | 19% influenza, 3% pneumoccous, 22% HBV, 5% VZV, 55% MMR, and 63% tetanus. Of those who had traveled, 9% HAV and 1% YF | High |
| Akan, 2016 [62] | Cross-sectional study | 2014 (June–Sept.) | family health care centres in Turkey | 596 | GPs | used, name not mentioned | Seasonal influenza | 27% | High |
| Asma, 2016 [63] | Cross-sectional study | 2015 (Jan.) | 6 university hospitals in Turkey | 642 | 177 (28%) physicians and 448 (71%) nurses | None | Seasonal influenza | 9% | Medium |
| Boey, 2018 [64] | Cross-sectional study | 2015 (Nov.–Dec.) | 13 hospitals and 14 nursing homes in Belgium | 5141 | 4506 hospital staff, 635 HCW nursing home staff. | HBM, HIM and ASE | Seasonal influenza | 2014: 62% (hospital) 2015: 65% (hospital) | High |
| Bonaccorsi, 2015 [65] | Cross-sectional study | 2010 (Oct.–Nov.) | Careggi University Teaching Hospital, Florance, Italy | 2576 | 10% physicians, 39% nurses, 23% students, 4% health care assistant, 15% other | None | Seasonal influenza | 18% | Medium |
| Castilla, 2013 [66] | Cross-sectional study | 2012 (Mar.–May) | PHC workers, Spain | 1956 | 47% GP, 10% paediatricians, 43% nurses | None | Seasonal influenza | 52–61% (2008–2011) | High |
| Ciftci, 2018 [67] | Cross-sectional study | 2015 (Sept.–Dec.) | University Hospital, Ankara, Turkey | 470 | Tertiary healthcare setting (18% physicians, 29% nurses, 11% assistants, 23% auxillary, 9% paramedics, 10% secretaries) | None | Seasonal influenza | 27% | High |
| Costantino, 2019 [68] | Cross sectional study | Influenza seasons 2016–2019 | University Hospital of Palermo, Italy | 1237 | Hospital HCW that had not received influenza vaccination | None | Seasonal influenza | 0% | High |
| Dedoukou, 2010 [69] | Cross-sectional study | 2018 (Oct.–Nov.) | 76 PHCs in Greece | 1617 | PHC: 35% physicians, 32% nurses, 23% paramedical/technical, 8% administrative | None | Seasonal influenza | 41% | Medium |
| deSante, 2010 [70] | Cross-sectional study | 2009 (Apr.) | 2 tertiary care hospitals in Pennsylvania, USA | 227 | House officers and attending physicians in emergency/internal medicine depts. | None | Seasonal influenza | 94% | Medium |
| Dominguez, 2013 [71] | Cross-sectional study | 2012 (Mar.–May) | PHC workers in 7 Spanish regions | 1749 | Familiy physician (47%), paediatrician (10%), nurses (43%). | None | Seasonal influenza | 51% | High |
| Durando, 2016 [72] | Cross-sectional study | 2013 (Oct.)–2014 (Apr.) | San Martino Teaching Hospital/Scientific Research Institute, Italy | 830 | HCW | None | Seasonal influenza | 26% | High |
| Ehrenstein, 2010 [73] | Cross-sectional study | 2006 (Feb.) | Tertiary care university hospital in Germany | 652 | HCW (physicians 36%, nurses 42%, administrators 22%) | None | Seasonal influenza | 34% | Medium |
| Giese, 2016 [74] | Cross-sectional study | 2013 | Ireland | 164 | HCW in a study group of Irish residents | None | Seasonal influenza | 28% | Medium |
| Gramegna, 2018 [75] | Cross-sectional study | 2016 | Italy | 144 | Italian Respiratory Society members | Seasonal influenza | 55% | Medium | |
| Gutknecht, 2016 [76] | Cross-sectional study | 2016 (Feb.–Mar.) | Poland | 77 | Physicians | None | Seasonal influenza | - | Low |
| Hagemeister, 2018 [77] | Cross-sectional study | 2015 (June-July) | University Hospital Würzburg, Germany | 677 | Physicians and nursing staff | None | Seasonal influenza | 55% | Medium |
| Harrison, 2016 [78] | Cross-sectional study | - | Vienna General Hospital, Austria | 116 | Nursing staff | None | HAV/HBV, DTP/Tdap, MMR, influenza, VZV, men, pneu | Seasonal influenza: 42%; Measles: 60% | Medium |
| Hopman, 2010 [79] | Cross-sectional study | 2008 (Nov.–Dec.) | All 8 University Medical Centers in NL | 1238 | HCW at medium and high risk for influenza | HBM, BIM, ASE | Seasonal influenza | 38% | Medium |
| Hulo, 2017 [80] | Cross-sectional study | 2014 | University Hospital Lille, France | 344 | HCW in the emergency departments and the IC units | None | Seasonal influenza | 18% | Medium |
| Johansen, 2012 [81] | Cross-sectional study | 2007 (May) | North and South Dakota | 155 | Randomly selected nurses (52% hospital, 13% clinic, 12% long term) | Triandis | Seasonal influenza | - | Medium |
| Kalemaki, 2020 [82] | Cross-sectional study | - | Crete, Greece | 260 | GPs | None | Seasonal influenza, measlesHBV, Tdap | Seasonal influenza 57%; Measles 26% HBV 68%; Tdap 47% | High |
| Karlsson, 2019 [83] | Cross-sectional study | - | Public hospitals in Finland | 2962 | Hospital personnel who may work with vaccinations (14% physicians) | None | Seasonal influenza | - | High |
| Kisic-Tepavcevic, 2017 [84] | Cross-sectional study | 2015 (Dec.) | Clinical Centre of Serbia, Belgrade, Serbia | 352 | HCW | None | HBV | 66% | High |
| Lehmann, 2015 [85] | Cross-sectional study | 2013 (Feb.–Apr.) | 20 hospitals in Belgium, Germany and NL | 1022 | 56% nurse, 15% physicians, 14% paramedics | None | Seasonal influenza | Total: 37%; Netherlands: 28%; Belgium: 53%; Germany: 36% | High |
| Maridor, 2017 [86] | Cross-sectional study | 2013 | 3 medium-sized, non-teaching hospitals, Switzerland | 252 | Nursing staff | None | Seasonal influenza | 58% | Medium |
| Napolitano, 2019 [87] | Cross-sectional study | 2018 (Sept.–Nov.) | 8 hospitals in Italy | 531 | Random sample of HCWs (29% physicians, 59% nurses) | None | HBV, influenza, MMR, VZV, pertussis | HBV: 98%; DTP: 91%; MMR: 64%; VZV: 59%; TBC: 50%; Influenza: 30%; Men C: 41% | High |
| Nowrouzi, 2014 [88] | Cross-sectional study | 2011 (Sept.–Nov.) | University of Toronto | 963 | Medical trainee’s (post graduate) | HBM | Seasonal (and pandemic) influenza | Seasonal influenza 69–76% (2008–2010) | High |
| Pielak, 2010 [89] | Cross-sectional study | 2005 (Apr.) | British Columbia, Canada | 719 | Immunization nurses of all health units and all physicians that administer vaccinations | TPB | Seasonal influenza | - | High |
| Prematunge, 2014 [90] | Cross-sectional study | 2010 (June) | Tertiary care hospital Ontario, Canada | 3275 | 35% nurse, 5% physician, 11% allied HCW’s, 22% administrative/clerical | None | Seasonal (and pandemic) influenza | Seasonal influenza: 74% | Medium |
| Quan, 2012 [91] | Retrospective cohort study | 2006–2011 | University of California Irvine Healthcare | 32,808 | all HCWs | None | Seasonal influenza | 44–92% (2007–2011) | Medium |
| Rabensteiner, 2018 [92] | Cross-sectional study | 2016 (Oct.–Dec.) | South Tyearolean Health Service, Italy | 4091 | 13% physicians, 20% administrative, 67% sanitary or executive non-medical staff | None | Seasonal influenza | 10% | High |
| Real, 2013 [93] | Cross-sectional study | - | Academic medical center in Lexington, USA | 318 | 80% clinical, 20% non-clinical | RPA | Seasonal influenza | 66% already received the vaccination or planned to get one soon | Medium |
| Rebmann, 2012 [94] | Cross-sectional study | 2011 (Apr.–June) | Saint Louis region, USA | 3188 | 54% non-hospital HCW, 46 % hospital HCW | None | Seasonal (and pandemic) influenza | 2010/11: 79% | High |
| Scatigna, 2017 [95] | Cross-sectional study | 2015 (Apr.–May) | San Salvatore Hospital, L’Aquila, Italy | 334 | Nurses 53%, physicians 23%, other 24% | None | HBV, influenza, MMR, VZV | - | Medium |
| Surtees, 2018 [96] | Cross-sectional study | 2016 | Tertiary referral hospital in Victoria, Australia | 1835 | HCW | None | Seasonal influenza | 97% | High |
| Taddei, 2014 [97] | Cross-sectional study | 2011 (June–Oct.) | 6 public hospitals in Florence, Italy | 436 | 59% nurses, 21% physicians, 13% nursing assistants, and 7% were midwives | None | MMR, VZV, Pertussis | 11% measles, 7% mumps, 17% rubella, 2% VZV, 7% pertussis | Medium |
| Tanguy, 2011 [98] | Cross-sectional study | 2009 (Nov.)–2010 (Feb.) | Tertiary care centre in Pays de la Loire Region, France | 532 | 24% medical staff, 65% nursing staff, 11% ancillary staff | None | Seasonal (and pandemic) influenza | 22% | Medium |
| Vallée-Tourange, 2018 [99] | Cross-sectional study | 2014 (June–July) | A single metropolitan hospital group, UK | 784 | 11% physicians, 36% nurses, 30% allied health professionals, 17% assistants | CME | Seasonal influenza | - | Medium |
| Verger, 2016 [100] | Cross-sectional study | 2014 (Apr.–July) | France | 1582 | GPs | None | Seasonal influenza, DTP, HBV | 72% influenza, 84% DTP, 86% HBV | High |
| Virseda, 2010 [101] | Cross-sectional study | 2009 (Dec.)–2010 (Jan.) | University Hospital 12 de Octubre, Madrid, Spain | 527 | HCW (23% physician, 29% nurse, 19% nursing assistant, 29% ancillary staff) | None | Seasonal (and pandemic) influenza | 50% | Medium |
| Wicker, 2010 [102] | Cross-sectional study | 2010 (Jan–May) | Frankfurt University Hospital, Germany | 1504 | Physicians 26%, nurses 35%, other HCW 23%, students 16% | None | Pertussis | 22% in last 10 years | Medium |
| Wilson, 2019 [103] | Cross-sectional study | Influenza seasons 2015–2017 | Southeast France | 1539 | 74% hospital nurses, 26% community nurses | None | Seasonal influenza | Both seasons: 24% at least one season: 34% | Medium |
| Wilson, 2020 [104] | Cross-sectional study | 2017–2018 | Southeast France | 1539 | 74% hospital nurses, 26% community nurses | None | Mandatory and recommended vaccines in France | 96% BCG, 73% DTP (<10 years), 61% HBV, 58% pertussis, 64% measles, 39% VZV, 27% seasonal influenza (last year) | Medium |
| Zhang, 2011 [105] and 2012 [106] | Cross-sectional study | 2010 (May-Oct.) | University Hospital London | 522 | Qualified nurses (79% working in hospital | None | Seasonal influenza | 36% | Medium |
* concerns vaccination uptake unless otherwise specified. ** Quality is assessed with the AXIS tool. A low score represents fulfillment of 1–9 out of 20 items, medium 10–14 and high 15–20 items (Exact scores are given in Supplementary Table S2). The following abbreviations are used (organized per column, in alphabetical order): Enrolment sites: USA = United States of America; UK = United Kingdom; NL = the Netherlands. Study populations: CD = Crohn’s Disease; GP = general practitioner; HCW = healthcare workers; HIV = human immunodefiency virus; HSCT = hematological stem cell transplantation; IBD = inflammatory bowel disease; ICP = immunocompromised patients; IS = immunosuppressive treatment; PHC = primary healthcare; RA = rheumatoid arthritis; SOT = solid organ transplantation; UC = colitis ulcerosa; VFR = travellers visiting friends and relatives. Theoretical frameworks: ASE = attitude, social influence and self-efficacy model; HBM = health belief model; KAP = knowledge, attitude, practice; HIM = the Health Intention Model; BIM = behavioral intention model; CME = Cognitive model of empowerment; RPA = risk perception attitude framework; Triandis = Triandis model of interpersonal behavior. Vaccinations: BCG = Bacillus Calmette-Guerin (vaccine for tuberculosis); DTP = diphtheria, tetanus, poliomyelitis; HAV = hepatitis A virus; HBV = hepatitis B virus; HZV = herpes zoster virus; JE = Japanese encephalitis; Men = meningococcal disease; menACWY = meningococcal serotype A, C, W and Y; MMR = measles, mumps, rubella; Pneu = pneumococcal disease; TBC = tuberculosis; Tdap = tetanus, diphtheria, acellular pertussis; VZV = varicella zoster virus, YF = yellow fever.