Abstract
Background
Legally blind patients are more prone to injury-related falls, which may lead to hip fractures, often necessitating total hip arthroplasty (THA), as a corrective procedure. Many of these patients have unique medical needs and have increased rates of perioperative complications following surgical procedures. However, there is limited information on the hospitalization data and perioperative complications in this population following guidelines such as THA. The purpose of this study was to evaluate the patient characteristics, demographics, and prevalence of perioperative issues among THA patients who were legally blind.
Methods
Using 2016–2019 data from the Nationwide Inpatient Sample (NIS), the incidence of perioperative complications, length of stay (LOS), and the cost of care (COC) among patients undergoing THA who were categorized as legally blind patients, compared to those who were not were analyzed. Propensity matching was conducted to consider associated factors that may influence perioperative complications.
Results
From 2016 to 2019, 367,856 patients underwent THA, according to the NIS. Of those, 322 (0.1%) patients were categorized as legally blind, and the remaining 367,534 (99.9%) patients were not identified as legally blind (control). Legally blind patients were significantly younger than the control group (65.4 years vs. 66.7 years, p < 0.001). After propensity matching, legally blind patients had longer LOS (3.9 days vs. 2.8, p = 0.04), increased discharges to another facility (45.9% vs. 29.3%, p < 0.001), and fewer discharges to home (21.4% vs. 32.2%, p = 0.02) than control patients.
Conclusions
The legally blind group had significantly longer LOS, higher rates of discharge to another facility, and lower rates of discharge to home compared to the control group. This data will help providers make informed decisions about patient care and resource allocation for legally blind patients undergoing THA.
Keywords: Perioperative complications, Legally blind, Total hip arthroplasty, Length of stay
1. Introduction
Up to 80 million persons in the United States (U.S.) have eye illnesses that could eventually cause blindness.1, 2, 3 Over 3 million are visually impaired or blind, with a yearly economic impact of around 35 billion dollars (USD).1, 2, 3 The legally blind population is expected to double by 2030 with the aging population.2 Moreover, vision loss has been shown to increase the risk of hip fractures.4,5
Total hip arthroplasty is the gold standard for treating end-stage osteoarthritis and is known to improve patients’ mobility and quality of life. Each year, more than one million THAs are carried out worldwide.6,7 As the prevalence of legally blind patients rises in the U.S., the demand for total hip arthroplasty (THA) has risen due to associated injuries.8 Previous studies have demonstrated an association between certain inpatient complications, such as falls and delirium, in the legally blind population.9, 10, 11 However, these studies are limited by small sample sizes and lack of information on other various complications that need to be considered in the postoperative setting.
Given the paucity of data on perioperative complications following THA in the legally blind population, further research is warranted. In this study, the Nationwide Inpatient Sample (NIS) Database was queried to assess the patient characteristics, demographics, and prevalence of postoperative problems among legally blind patients who received THA. We hypothesize that legally blind patients will have higher rates of perioperative complications, longer hospitalizations, and higher costs associated with their care than non-legally blind patients.
2. Methods
2.1. Database description
This study used the NIS database, provided by the Healthcare Cost and Utilization Project and made available through the Agency for Healthcare Research and Quality.12 More than 7 million unweighted hospital stays are tracked by the NIS annually. The high sample size of the NIS enables the examination of groups with features, such as legally blind patients undergoing THA, and the creation of regional and national estimations. Data on patient demographics, length of stay (LOS), hospital costs, discharge status, perioperative complications, and several other factors are all included in the NIS database. The International Classification of Diseases (ICDs), Tenth Revision, Clinical Modification/Procedure Coding System is used for the 2016–2019 revision.
2.2. Data acquisition
The project was exempt from Institutional Review Board (IRB) because the de-identified data were easily accessible to the public. All patients having THA-related ICD-10, Tenth Revision, and Clinical Modification/Procedure Coding System (CMP) codes were included in this study. Patients were then divided into two cohorts: those who were legally blind and those who were not (control). ICD codes were used for this study, outlined in Appendix A. Data were taken from the years 2016 through 2019.
In examining demographic characteristics, age, sex, ethnicity, and the presence of obesity were all considered. Also included were comorbidities and medical complications, such as postoperative anemia, acute renal failure (ARF), deep vein thrombosis (DVT), pulmonary embolism (P.E.), myocardial infarction (MI) and pneumonia in addition to surgical complications like periprosthetic infections (PPIs), prosthetic dislocations, and periprosthetic fractures.
Also, the post-hospitalization discharge destinations of the patients (home/routine, alternative facility, and home healthcare (HHC)) were analyzed. Finally, we also analyzed the length of stay and cost of care. ICD codes listed in Appendix A were utilized to identify preoperative comorbidities and postoperative complications.
2.3. Statistical evaluation
SPSS version 27.0 was used for all statistical analyses (IBM; Armonk, NY, USA). Demographic information about patients was initially compiled using descriptive statistics. We carried out a matched and unmatched analysis. Using the preoperative variables, a 1:1 propensity matching algorithm was run. Propensity matching was conducted for age, sex, race, obesity, diabetes with complications, and diabetes without complications. When examining numerical variables, t-tests were employed. Binomial variables were examined using chi-squared analysis. When the incidence number was below 5, Fischer exact testing was conducted. Statistical significance was defined for all tests as a p-value of 0.05 or less. Using a ratio of incidence in the legally blind group to the incidences in the control group, the odds ratios and their corresponding 95% confidence intervals were calculated.
3. Results
367,856 patients who underwent THA were identified. Within that population, 367,534 (99.9%) patients were not identified as legally blind (control), and 322 (0.1%) patients were legally blind (Table 1).
Table 1.
Patient demographic characteristics of legally blind patients and the control group patients.
| Legally Blind Group (322) | Control Group (367534) | Significance | |
|---|---|---|---|
| Age in years | 65.4 (SD = 9.8) | 66.7 (SD = 9.5) | <0.001 |
| Female | 189 (58.7%) | 205553 (55.9%) | <0.001 |
| Obesity | 62 (19.3%) | 79857 (21.7%) | 0.16 |
| Race | |||
| Caucasian | 260 (80.7%) | 302482 (82.3%) | <0.001 |
| African American | 31 (9.6%) | 27351 (7.4%) | <0.001 |
| Hispanic | 12 (3.7%) | 13022 (3.5%) | <0.001 |
| Asian | 1.8% | 3404 (0.9%) | <0.001 |
| Native American | 0% | 1122 (0.3%) | <0.001 |
| Other | 0.9% | 6020 (0.2%) | <0.001 |
Bolded values indicate statistical significance.
Numbers between 1 and 10 were not reported per the healthcare cost and utilization project data agreement.
3.1. Patient demographics
Legally blind patients were significantly younger than the control group (65.4 years vs. 66.7 years, p < 0.001). The proportion of females was significantly larger in the legally blind group than in the controls (58.7 vs. 55.9, p < 0.001). Additionally, in looking at patient ethnicity, for both groups, there was a greater proportion of Caucasians compared to other races such as African American, Asian or Pacific Islander, and Native American (Table 1).
3.2. Unmatched patient admission and discharge characteristics
Patients in the legally blind group (72605.31 USD) had a significantly larger expenditure in comparison to those in the control group (66874.82 USD, p < 0.001). Additionally, patients in the legally blind group had a significantly longer length of stay in the hospital (3.9 ± 8 days) than those in the control group (2.3 ± 1.9 days, p < 0.001). Tobacco-related disorders were significantly higher in the control group (17.3%) in comparison to the legally blind group (12.4%, p = 0.03). In addition, legally blind patients were significantly more likely to be discharged to another facility (45.9%) than patients in the control group (18.3%, p < 0.001). A significantly higher proportion of control group patients were found to be discharged to home (38.9%) or to Home Healthcare (42.3%) than those in the legally blind group (p < 0.001). There were no significant differences in comparing diabetes characteristics between the two groups (Table 2).
Table 2.
Unmatched analysis - patient admission and discharge characteristics of legally blind patients and the control group patients.
| Variable | Legally Blind Group (322) | Control Group (n = 367534) | Significance |
|---|---|---|---|
| Length of Stay (Days) | 3.9 (SD = 8) | 2.3 (SD = 1.9) | <0.001 |
| Total Charges (USD) | 72605.31 (SD = 56843.96) | 66874.82 (SD = 47833.50) | 0.03 |
| Tobacco-Related Disorder | 40 (12.4%) | 63668 (17.3%) | 0.01 |
| Diabetes Without Complications | 40 (12.4%) | 36788 (10%) | 0.16 |
| Diabetes With Complications | 0.3% | 712 (0.2%) | 0.47 |
| Patient Discharge | |||
| Home/Routine | 69 (2.1%) | 143169 (38.9%) | <0.001 |
| Another Type of Facility | 148 (45.9%) | 67350 (18.3%) | <0.001 |
| Home Healthcare (HHC) | 104 (3.2%) | 155460 (42.3%) | <0.001 |
Bolded values indicate statistical significance.
Numbers between 1 and 10 were not reported per the healthcare cost and utilization project data agreement.
3.3. Matched patient admission and discharge characteristics
After marching, there were 322 patients in the legally blind group and 311 patients in the control group. After matching, the average LOS continued to be longer for the legally blind group, with a mean of 3.9 days, than in the control group, with a mean of 2.8 days (p = 0.04). After propensity matching, legally blind patients were more likely to be discharged to another type of facility (45.9%) in comparison to the control group (29.3%, p = 0.02). In addition, control patients had a much higher rate of discharge to home (32.2%) than patients in the legally blind group (21.4%, p < 0.001). The control group had a significantly higher incidence of Home Healthcare use (38.3%) than the legally blind group (32.3%, p = 0.04) (Table 3).
Table 3.
Matched analysis – patient admission and discharge characteristics of legally blind patients and the control group patients.
| Variable | Legally Blind Group (322) | Control Group (311) | Significance |
|---|---|---|---|
| Length of Stay (Days) | 3.9 (SD = 8.02) | 2.8 (SD = 5.4) | 0.04 |
| Total Charges (USD) | 72605.31 (SD = 56843.96) | 71867.04 (67713.57) | 0.15 |
| Patient Discharge | |||
| Home/Routine | 69 (21.4%) | 100 (32.2%) | 0.02 |
| Another Type of Facility | 148 (45.9%) | 91 (29.3%) | <0.001 |
| Home Healthcare (HHC) | 104 (32.3%) | 119 (38.3%) | 0.04 |
Bolded values indicate statistical significance.
3.4. Perioperative complications
The analysis found that legally blind patients had a significantly greater incidence of acute renal failure (4.9%) than the control group (2.5%, p = 0.01). Additionally, we observed that there was a much higher incidence of blood loss anemia in legally blind patients (23.9%) than in the control group (19.6%, p = 0.03). Contrarily, compared to controls (3.5%), patients who were legally blind (7.4%) required considerably more blood transfusions (0.001). Other postoperative complications were insignificant (pneumonia: p = 0.58, pulmonary embolism: p = 0.34, periprosthetic fracture: p = 0.19, periprosthetic dislocation: p = 0.17, periprosthetic infection: p = 0.43, and periprosthetic mechanical complication: p = 0.29). Lastly, the two groups had no difference in mortality rates (p = 0.25) (Table 4).
Table 4.
Unmatched Analysis – Postoperative complications differences between Legally Blind Patients and the Control Group patients.
| Post Operative Variables | Legally Blind Group (322) | Control Group (367534) | Odds Ratio (Legally blind/Control Group) | Odds Ratio 95% Confidence Interval | Significance |
|---|---|---|---|---|---|
| Died During Hospitalization | 0.3% | 331 (0.1%) | 3.45 | (0.48, 24.68) | 0.25 |
| Acute Renal Failure | 16 (4.9%) | 9114 (2.4%) | 2.06 | (1.24, 3.40) | 0.01 |
| Myocardial Infarction | 0% | 142 (0.04%) | a | a | a |
| Blood Loss Anemia | 77 (23.9%) | 71894 (19.6%) | 1.29 | (1.00, 1.67) | 0.03 |
| Pneumonia | 0.3% | 972 (0.3%) | 1.18 | (0.17, 8.38) | 0.58 |
| Blood Transfusion | 24 (7.4%) | 12878 (3.5%) | 2.21 | (1.46, 3.36) | <0.001 |
| Pulmonary Embolism | 0.3% | 474 (0.1%) | 2.41 | (0.38, 17.21) | 0.34 |
| Deep Vein Thrombosis | 0% | 562 (0.2%) | a | a | a |
| Periprosthetic Fracture | 6 | 4419 (1.2%) | 1.56 | (0.69, 3.50) | 0.19 |
| Periprosthetic Dislocation | 7 | 5144 (1.4%) | 1.57 | (0.74.3.31) | 0.17 |
| Periprosthetic Infection | 4 | 3827 (1%) | 1.19 | (0.45, 3.21) | 0.43 |
| Periprosthetic Mechanical Complication | 0.3% | 2855 (0.8%) | 0.39 | (0.6, 2.84) | 0.29 |
| Superficial SSI | 0% | 43 (0.01%) | a | a | a |
| Deep SSI | 0% | 30 (0.01%) | a | a | a |
| Wound Dehiscence | 0% | 307 (0.08%) | a | a | a |
Bolded values indicate statistical significance.
Numbers between 1 and 10 were not reported per the healthcare cost and utilization project data agreement.
Since incidence was 0 in one group, odds ratio and significance values could not be computed.
After propensity matching, the two groups had no significant differences in postoperative complications.
4. Discussion
The population of legally blind patients is increasingly growing in the United States. Previous literature has demonstrated a higher risk of associated orthopedic injuries in this population, specifically hip dislocations and fractures.13 However, this population's information regarding postoperative complications following THA is limited. Our study aims to contribute to the available literature by examining perioperative factors in this population using a large database sample. We discovered that legally blind patients are met with more extended stays, fewer home discharges, and more discharges to another facility after orthopedic procedures such as total hip arthroplasty compared to patients who are not legally blind.
Our data suggest that legally blind patients had significantly longer LOS than the control group, evident even after propensity-matched analysis. This aligns with prior work by Harris and Wright,3 where the authors found that hospitalized patients with severe impairment and blindness (SVI/B) had a significantly longer LOS than those without SVI/B. Moreover, the authors found that the hospital charges were not significantly different between the groups, as seen in our study. Other studies have shown that severe vision loss was associated with longer mean LOS and a higher cost of care.14, 15, 16, 17 Morse et al.,14 found that Medicare beneficiaries with severe vision loss had a 4% longer LOS than patients without vision loss. However, it is essential to note that none of these studies evaluated perioperative complications in legally blind patients after orthopedic procedures such as THA. Our patient population includes younger hospitalized patients, which may help to explain the disparities between longer LOS and no difference in COC. Also, it has been demonstrated in the past that a rise in LOS is not always linked to hospital expenses.18,19
Legally blind patients had higher rates of being discharged to another facility and lower rates of being discharged home after hospital discharge than the control group, which was similarly seen in previous studies.3 Legally blind individuals' struggles adhering to post-discharge therapy could be a factor in the decreased rate of home release.3 Prior research has demonstrated that maintaining compliance with treatments requiring injections or infusions at home is difficult and necessitates facilities with appropriate supervision (rehabilitation, nursing home, etc.).20 Thus, it is reasonable to conclude that legally blind patients require more support after THA and require discharge to subacute facilities to recover compared to patients who are not legally blind.
The existence of health inequities among patients who are legally blind and who are offered primary THA is another possible finding of this study. According to the 2020 Census Bureau's estimate of the racial and ethnic makeup of the United States, Caucasians (61.9%) made up the majority of the population, followed by Hispanic/Latinos (18.7%), African-Americans (12.4%), Asians (6%), Native Americans (1.1%), and Pacific Islanders (0.2%).21 We found that the control group showed a significant ethnic disparity in THA patients, with Caucasians predominating (82.3%), followed by African Americans (7.4%), Hispanics (3.5%), Asian or Pacific Islanders (0.9%), and Native Americans (0.3%). This trend was similarly modeled in the legally blind group, as Caucasians predominated again, with over 80.7% of patients identifying as Caucasian, followed by African American (9.6%), Hispanic (3.7%), and Asian or Pacific Islander (1.8%). The gap shown in our research gives insight into a significant subject that calls for further discussion, even though our primary focus was on mortality, duration of stay, and perioperative complications in legally blind patients receiving THA.
5. Limitations
We are aware that the NIS, the most extensive database currently available and includes all participants, may be susceptible to errors in certain aspects, such as the long-term results of THA in legally blind patients. Even though the NIS data is precise (specificity >92%), this data can occasionally be deficient.
Moreover, utilizing ICD codes to compare patient samples could reduce the validity of the findings. A comparison of precise data from institutions would be more accurate because this might only partially represent the features of the patient group. Also, a matched analysis of age, sex, obesity, and diabetes (with or without problems) diminished the importance of several postoperative complications. With a high sample size, this study offers important information about the characteristics of patients who are legally blind and receiving THA.
6. Conclusions
To the best of our knowledge, this is the first large-database study which has examined perioperative complications and hospital admission characteristics of legally blind patients undergoing THA. Legally blind patients are met with longer LOS and more discharges to other facilities after procedures such as THA. This study provides information on the perioperative results of primary THA in legally blind patients to providers, healthcare organizations, and clinicians. When assessing hospital expenditures for legally blind patients, it is crucial to consider the higher rate of perioperative problems in this patient group. This data will help providers make informed decisions about patient care and resource utilization for legally blind patients undergoing THA.
Funding/sponsorship
This research received no specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Institutional ethical committee approval
Due to the lack of patient identification and the fact that the National Inpatient Sample database is blinded, this study complied with the requirements of the Institutional Review Board for exemption from the complete review.
Authors contribution
Nikit Venishetty: Writing- Original draft preparation, Data curation, Writing- Review & Editing. Garrett Sohn: Investigation, Writing- Review & Editing. Ivy Nguyen: Writing- Review & Editing. Meesha Trivedi: Writing- Review & Editing. Varatharaj Mounasamy Software, Validation, Formal Analysis, Methodology. Senthil Sambandam: Conceptualization, Methodology, Writing- Review & Editing.
Declaration of competing interest
None.
Acknowledgments
None.
Appendix A. ICD Codes
| Obese Codes | Legally Blind Code |
Comorbidities codes | Medical Complications codes | Surgical Complications codes |
|---|---|---|---|---|
| E660 | H54.8 | Diabetes without complications | Acute renal Failure | Periprosthetic fracture |
| E6601 | E119 | N170, N171, N172, N178, N179 | T84010A, T84011A, T84012A, T84013A, T84018A, T84019A, M9665, M96661, M96662, M96669, M96671, M96672, M96679, M9669, M9701XA, M9702XA, | |
| E6609 | Diabetes with complications | Myocardial Infarction | M9711XA, M9712XA | |
| E661 | E1169 | I2101, I2102, I2111, I2113, I12114, I12119, I2121, I12129, I21A1 | Periprosthetic dislocation | |
| E662 | Tobacco related disorder | Blood loss anemia | T84020A, T84021A, T84022A, T84023A, T84028A, T84029A | |
| E668 | Z87891 | D62 | Periprosthetic mechanical complications | |
| E669 | Pneumonia | T84090A, T84091A, T84092A, T84093A, T84098A, T84099A | ||
| Z6830 | J189, J159, J22 | Periprosthetic Infection | ||
| Z6831 | Blood transfusion | T8450XA, T8451XA, T8452XA, T8453XA, T8454XA, T8459XA | ||
| Z6832 | 30233N1 | Superficial SSI | ||
| Z6833 | Pulmonary embolism | T8141XA | ||
| Z6834 | I2602, I2609, I2692, I2699 | Deep SSI | ||
| Z6835 | DVT | T8142XA | ||
| Z6836 | I82401, I82402, I82403, I82409, I82411, I82412, I82413, I82419, I82421, I82422, I82423, I82429, I82431, I82432, I82433, I82439, I82441, I82442, I82443, I82449, I82491, I82492, I82493, I82499, I824Y1, I824Y2, I824Y3, I824Y9, I824Z1, I824Z2, I824Z3, I824Z4 | Wound Dehiscence | ||
| Z6837 | T8130XA, T8131XA, T8132XA | |||
| Z6838 | ||||
| Z6839 |
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