The nature of increased hospital use in poor neighbourhoods: findings from a Canadian inner city

Sex Differences in Complications Following Total Hip Arthroplasty: A Population-Based Study

BACKGROUND

The relationship between sex and outcomes, especially complications, after total hip arthroplasty (THA) has not been well established. This study aimed to identify if patient biological sex significantly impacted complications after THA in Ontario, Canada.

METHODS

A population-based retrospective cohort study of patients undergoing primary THA in Ontario from April 1, 2015, to March 31, 2020 was conducted. The primary outcome was major surgical complications within a year post-surgery (a composite of revision, deep infection requiring surgery, and dislocation). Secondary outcomes included the individual component of the composite primary outcome and major medical complications within 30 days. Proportional hazards regression calculated the adjusted hazards ratio (aHR) for major surgical complications in men relative to women, adjusting for age, co-morbidities, neighborhood income quintile, surgeon and hospital volume, and year of surgery.

RESULTS

A total of 67,077 patients (median age 68 years; 54.1% women) from 61 hospitals were included; women were older with a higher prevalence of frailty. Women had a higher rate of major surgical complications within one year of surgery compared to men (2.9 versus 2.5%, adjusted OR [odds ratio] 1.19, 95%CI [confidence interval] 1.08 to 1.33, P = 0.0009). Conversely, men had a higher risk for medical complications within 30 days (6.3 versus 2.7%, P < 0.001).

CONCLUSION

Observable sex disparities exist in post-THA complications; women face surgical complications predominantly, while medical complications are more prevalent in men. These insights can shape preoperative patient consultations.

Development of a low resource exercise rehabilitation application for musculoskeletal disorders to help underserved patients in a primary care setting

OBJECTIVE

We set out to create a Family Medicine EHR (electronic health record) embedded exercise application. This was done to evaluate the utility of the exercise app for providers and to understand the usefulness of the exercise app from the perspective of patients.

METHODS

This exercise application was developed through an iterative process with repeated pre-testing and feedback from an interprofessional team and embedded into the EHR at an academic family medicine clinic. Anecdotal feedback from patients was used to inform pre-testing adaptations.

RESULTS

The application required six iterations prior to clinical utility. It had several features that clinicians and patients felt were beneficial. These features involved a customizable exercise directory with pre-made templated plans which could be further modified. To overcome accessibility barriers, the application was developed to include digital and printable copies with an integrated direct email option for ease of remote sharing with patients.

CONCLUSION

A customizable, open-source exercise application was developed to facilitate provider exercise prescription and support patient self-management. This project may be useful for other providers interested in developing similar programs to address musculoskeletal conditions in their patients. Next steps are to undertake pilot testing of the app with broader provider and patient feedback.

Access to hip arthroplasty and rates of complications in different socioeconomic groups : a review of 111,000 patients in a universal healthcare system

AIMS

Total hip arthroplasty (THA) is one of the most successful surgical procedures. The objectives of this study were to define whether there is a correlation between socioeconomic status (SES) and surgical complications after elective primary unilateral THA, and investigate whether access to elective THA differs within SES groups.

METHODS

We conducted a retrospective, population-based cohort study involving 202 hospitals in Ontario, Canada, over a 17-year period. Patients were divided into income quintiles based on postal codes as a proxy for personal economic status. Multivariable logistic regression models were then used to primarily assess the relationship between SES and surgical complications within one year of index THA.

RESULTS

Of 111,359 patients who underwent elective primary THA, those in the lower SES groups had statistically significantly more comorbidities and statistically significantly more postoperative complications. While there was no increase in readmission rates within 90 days, there was a statistically significant difference in the primary and secondary outcomes including all revisions due (with a subset of deep wound infection and dislocation). Results showed that those in the higher SES groups had proportionally more cases performed than those in lower groups. Compared to the highest SES quintile, the lower groups had 61% of the number of hip arthroplasties performed.

CONCLUSION

Patients in lower socioeconomic groups have more comorbidities, fewer absolute number of cases performed, have their procedures performed in lower-volume centres, and ultimately have higher rates of complications. This lack of access and higher rates of complications is a "double hit" to those in lower SES groups, and indicates that we should be concentrating efforts to improve access to surgeons and hospitals where arthroplasty is routinely performed in high numbers. Even in a universal healthcare system where there are no penalties for complications such as readmission, there seems to be an inequality in the access to THA. Cite this article: Bone Joint J 2022;104-B(5):589-597.

Association of Surgical Experience With Risk of Complication in Total Hip Arthroplasty Among Patients With Severe Obesity

IMPORTANCE

Severe obesity is a risk factor for major early complications after total hip arthroplasty (THA).

OBJECTIVE

To determine the association between surgeon experience with THA in patients with severe obesity and risk of complications.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective population-based cohort study was performed in Ontario, Canada, from April 1, 2007, to March 31, 2017, with data analysis performed from March 2020 to January 2021. A cohort of patients who received a primary THA for osteoarthritis and who also had severe obesity (body mass index [calculated as weight in kilograms divided by height in meters squared] ≥40) at the time of surgery was defined. These patients were identified using the Canadian Institute for Health Information Discharge Abstract Database and physician claims from the Ontario Health Insurance Plan. Generalized estimating equations were used to determine the association between overall THA and severe obesity-specific THA surgeon volume and the occurrence of complications after controlling for potential confounders. The study hypothesized that surgeon experience specific to patients with severe obesity could further reduce the risk of complications.

EXPOSURES

Primary THA.

MAIN OUTCOMES AND MEASURES

Complications were considered as a composite outcome (revision, infection requiring surgery, or dislocation requiring reduction), within 1 year of surgery. This was defined before the study, as was the study hypothesis.

RESULTS

A total of 4781 eligible patients was identified. The median age was 63 (interquartile range [IQR], 56-69) years, and 3050 patients (63.8%) were women. Overall, 186 patients (3.9%) experienced a surgical complication within 1 year of surgery. The median overall THA surgeon volume was 70 (IQR, 46-106) cases/y, whereas the median obesity-specific surgeon volume was 5 (IQR, 2-9) cases/y. After controlling for patient and hospital factors, greater obesity-specific THA surgeon volume (adjusted odds ratio per additional 10 cases, 0.65 [95% CI, 0.47-0.89]; P = .007), but not greater overall THA surgeon volume (adjusted odds ratio per 10 additional cases, 0.97 [95% CI, 0.93-1.02]; P = .24), was associated with a reduced risk of complication.

CONCLUSIONS AND RELEVANCE

Increased surgeon experience performing THA in patients with severe obesity was associated with fewer major surgical complications. These findings suggest that surgeon experience is required to mitigate the unique anatomical challenges posed by surgery in patients with severe obesity. Referral pathways for patients with severe obesity to surgeons with high obesity-specific THA volume should be considered.

Analysis of the relationship between surgeon procedure volume and complications after total knee arthroplasty using a propensity-matched cohort study

Objectives

This study aimed to identify a threshold in annual surgeon volume associated with increased risk of revision (for any cause) and deep infection requiring surgery following primary elective total knee arthroplasty (TKA).

Design

A propensity score matched cohort study.

Setting

Ontario, Canada.

Participants

169 713 persons who received a primary TKA between 2002 and 2016, with 3-year postoperative follow-up.

Main outcome measures

Revision arthroplasty (for any cause), and the occurrence of deep surgical infection requiring surgery.

Results

Based on restricted cubic spline analysis, the threshold for increased probability of revision and deep infection requiring surgery was <70 cases/year. After matching of 51 658 TKA recipients from surgeons performing <70 cases/year to TKA recipients from surgeons with greater than 70 cases/year, patients in the former group had a higher rate of revision (for any cause, 2.23% (95% Confidence Interval (CI) 1.39 to 3.07) vs 1.70% (95% CI 0.85 to 2.55); Hazard Ratio (HR) 1.33, 95% CI 1.21 to 1.47, p<0.0001) and deep infection requiring surgery (1.29% (95% CI 0.44 to 2.14) vs 1.09% (95% CI 0.24 to 1.94); HR 1.33, 95% CI 1.17 to 1.51, p<0.0001).

Conclusions

For primary TKA recipients, cases performed by surgeons who had performed fewer than 70 TKAs in the year prior to the index TKA were at 31% increased relative risk of revision (for any cause), and 18% increased relative risk for deep surgical infection requiring surgery, at 3-year follow-up.

The Association Between Surgeon Age and Early Surgical Complications of Elective Total Hip Arthroplasty: Propensity-Matched Cohort Study (122,043 Patients)

BACKGROUND

The aim of this study was to examine the relationship between surgeon age and early surgical complications following primary total hip arthroplasty (THA), within a year, in Ontario, Canada.

METHODS

In a propensity-matched cohort, we defined consecutive adults who received their first primary THA for osteoarthritis (2002-2018). We obtained hospital discharge abstracts, patient's demographics and physician claims. Age of the primary surgeon was determined for each procedure and used as a continuous variable for spline analysis, and as a categorical variable for subsequent matching (young <45; middle-age 45-55; older >55). The primary outcome was early surgical complications (revision, dislocation, infection). Secondary analyses included high-volume vs low-volume surgeons (≤35 THA per year).

RESULTS

We identified 122,043 THA recipients, 298 surgeons with median age 49 years. Younger, middle-aged, and older surgeons performed 39%, 29%, and 32% THAs, respectively. Middle-aged surgeons had the lowest rate of complications. Younger surgeons had a higher risk of composite complications (odds ratio [OR] 1.25, 95% confidence interval [CI] 1.09-1.44, P = .002), revision (OR 1.28, 95% CI 1.07-1.54, P = .007), and infection (OR 1.39, 95% CI 1.12-1.71, P = .003). Older surgeons also had higher risk for composite complications (OR 1.18, 95% CI 1.03-1.36, P = .019), revision (OR 1.33, 95% CI 1.10-1.62, P = .004), and dislocation (OR 1.37, 95% CI 1.08-1.73, P = .009). However, when excluding low-volume surgeons, older high-volume surgeons had similar complications to middle-aged surgeons.

CONCLUSION

Younger surgeons (<45 years) had the highest recorded complications rate while the lowest rate was for surgeons aged 45-55. Volume rather than age was more important in determining rate of complications of older surgeons.

LEVEL OF EVIDENCE

IV.

Early Surgical Complications of Total Hip Arthroplasty in Patients With Morbid Obesity: Propensity-Matched Cohort Study of 3683 Patients

BACKGROUND

The aim of this study is to determine whether the high risk of surgical complications within 1 year of total hip arthroplasty (THA) is due to associated comorbidities or morbid obesity alone as measured by body mass index (BMI ≥ 40 kg/m²).

METHODS

Population-based retrospective cohort study was conducted of all adults in Ontario undergoing primary THA for osteoarthritis (2012-2018). All patients were followed for 1 year. Outcomes were compared among matched groups (hypertension, diabetes, chronic obstructive pulmonary disease, frailty, congestive heart failure, coronary artery disease, asthma, and Charlson score). Primary outcome measure was major surgical complications within 1 year (composite of deep infection requiring surgery, dislocation requiring closed or open reduction, and revision surgery).

RESULTS

A total of 3683 patients with morbid obesity were matched and had a significantly greater risk of major complications within 1-year (132 [3.6%] vs 54 [1.5%]; hazard ratio [HR] 2.54, 95% confidence interval [CI]; 1.98-3.25). This included greater risk for deep infection requiring surgery (100 [2.8%] vs 26 [0.7%]; HR 3.85, 95% CI; 2.70-45.48) and revision arthroplasty (86 [2.4%] vs 34 [0.9%]; HR 2.61, 95% CI; 1.92-3.55). Operative time was also longer with a median 116 (99-138) vs 102 (87-121) minutes. There were no significant differences in hospital stay, cost of acute care episode, or medical complications.

CONCLUSION

Patients' large body habitus seems to contribute to the increased risk of surgical complications within 1-year of THA. Future research is needed to identify ways of mitigating surgical complications such as centralizing care for this complex group of patients in specialist centers.

Socioeconomic and citizenship inequalities in hospitalisation of the adult population in Italy

BACKGROUND

Higher levels of hospital admissions among people with lower socioeconomic level, including immigrants, have been observed in developed countries. In Europe, immigrants present a more frequent use of emergency services compared to the native population. The aim of our study was to evaluate the socioeconomic and citizenship differences in the hospitalisation of the adult population in Italy.

METHODS

The study was conducted using the database created by the record linkage between the National Health Interview Survey (2005) with the National Hospital Discharge Database (2005-2014). 79,341 individuals aged 18-64 years were included. The outcomes were acute hospital admissions, urgent admissions and length of stay (1-7 days, > = 8 days). Education level, occupational status, self-perceived economic resources and migratory status were considered as socioeconomic determinants. A multivariate proportional hazards model for recurrent events was used to estimate the risk of total hospital admissions. Logistic models were used to estimate the risk of urgent hospitalisation as well as of length of stay.

RESULTS

Low education level, the lack of employment and negative self-perceived economic resources were conditions associated with the risk of hospitalisation, a longer hospital stay and greater recourse to urgent hospitalisation. Foreigners had a lower risk of hospitalisation (HR = 0.75; 95% CI:0.68-0.83) but a higher risk of urgent hospitalisation (OR = 1.36; 95% CI:1.18-1.55) and more frequent hospitalisations with a length of stay of at least eight days (OR = 1.19; 95% CI:1.02-1.40).

CONCLUSIONS

To improve equity in access, effective primary, secondary and tertiary prevention strategies must be strengthened, as should access to appropriate levels of care.

No Difference in Outcomes Between Short and Longer-Stay Total Joint Arthroplasty with a Discharge Home: A Propensity Score-Matched Analysis Involving 46,660 Patients

BACKGROUND

Outcomes following total hip arthroplasty (THA) and total knee arthroplasty (TKA) with a short length of hospital stay have been reported; however, most studies have not accounted for an inherent patient selection bias and discharge disposition. The purpose of this study was to utilize a propensity score to match and compare the outcomes of patients undergoing THA or TKA with short and longer lengths of stay with a discharge directly home.

METHODS

An administrative database from Ontario, Canada, which has a single-payer health-care system, was retrospectively reviewed to identify patients who underwent THA or TKA from 2008 to 2016. Patients were subsequently stratified into 2 groups based on their length of stay: short length of stay (≤2 days; thereafter referred to as short stay) and longer length of stay (>2 days; thereafter referred to as longer stay). Using a propensity score, patients who underwent short-stay THA or TKA were matched to patients who underwent longer-stay THA or TKA. Matching was based on 15 demographic, medical, and surgical factors. Our primary outcomes included postoperative complications, health-care utilization (readmission and emergency department presentation), and health-care costs.

RESULTS

Overall, 89,656 TKAs (14,645 short stays and 75,011 longer stays) and 52,610 THAs (9,426 short stays and 43,184 longer stays) were included in this study. Patients who underwent short-stay THA or TKA were significantly more likely (p < 0.05) to be younger, male, healthier, and from a higher socioeconomic status and to have undergone the procedure with a higher-volume surgeon. Over 95% of short-stay cases were successfully matched to longer-stay cases, and we found no significant difference in complications, health-care utilization, and costs between patients on the basis of the length of stay.

CONCLUSIONS

Patients undergoing short-stay THA or TKA with a discharge home were more likely to be younger, healthy, male patients from a higher socioeconomic status. Higher-volume surgeons are also more likely to perform short-stay THA or TKA. These characteristics confirm the previously held belief that a selection bias exists when comparing cohorts based on time to discharge. When comparing matched cohorts of patients who underwent short-stay and longer-stay THA or TKA, we observed no difference in outcomes, suggesting that a short stay with a discharge home in the appropriately selected patient is safe following THA or TKA.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Association Between Surgical Approach and Major Surgical Complications in Patients Undergoing Total Hip Arthroplasty

IMPORTANCE

Controversy exists about the preferred surgical approach for total hip arthroplasty (THA).

OBJECTIVE

To determine whether an anterior approach is associated with lower risk of complications than either a lateral or posterior approach.

DESIGN, SETTING, AND PARTICIPANTS

Population-based retrospective cohort study of all adults in Ontario, Canada, who had undergone primary THA for osteoarthritis between April 1, 2015, and March 31, 2018. All patients were followed up over a 1-year period (study end date, March 31, 2019).

EXPOSURES

Surgical approach (anterior vs lateral/posterior) for THA.

MAIN OUTCOMES AND MEASURES

Major surgical complications within 1 year (composite of deep infection requiring surgery, dislocation requiring closed or open reduction, or revision surgery). Outcomes were compared among propensity-score matched groups using Cox proportional hazards regression.

RESULTS

Of the 30 098 patients (mean [SD] age, 67 years [10.7 years]; 16 079 women [53.4%]) who underwent THA, 2995 (10%) underwent the anterior approach; 21 248 (70%), the lateral approach; and 5855 (20%) the posterior approach performed at 1 of 73 hospitals by 1 of 298 surgeons. All patients were followed up for 1 year. Compared with those undergoing the lateral or posterior approach, patients undergoing an anterior approach were younger (mean age, 65 vs 67 years; standardized difference, 0.17); had lower rates of morbid obesity (4.8% vs 7.6%; standardized difference, 0.12), diabetes (14.2% vs 19.9%; standardized difference, 0.15), and hypertension (53.4% vs 62.9%; standardized difference, 0.19); and were treated by higher-volume surgeons (median range, 111 procedures; interquartile range, 69-172 vs 77 procedures, interquartile range, 50-119 in the prior year; standardized difference, 0.55). Compared with 2993 propensity-score matched patients undergoing a lateral or posterior approach, the 2993 matched patients undergoing anterior approaches had a significantly greater risk of a major surgical complication (61 patients [2%] vs 29 patients [1%]; absolute risk difference, 1.07%; 95% CI, 0.46%-1.69%; hazard ratio, 2.07; 95% CI, 1.48 to 2.88).

CONCLUSIONS AND RELEVANCE

Among patients undergoing total hip arthroplasty, an anterior surgical approach compared with a posterior or lateral surgical approach was associated with a small but statistically significant increased risk of major surgical complications. The findings may help inform decisions about surgical approach for hip arthroplasty, although further research is needed to understand pain and functional outcomes.

Factors associated with emergency department presentation after total joint arthroplasty: a population-based retrospective cohort study

BACKGROUND

Unplanned visits to the emergency department after total joint arthroplasty are far more common than unplanned readmissions. Our objectives were to characterize the prevalence of presentation to an emergency department for any reason after total joint arthroplasty and to identify risk factors for such visits.

METHODS

Using health administrative databases, we conducted a population-based retrospective cohort study of adults (19-89 yr of age) who received their first primary elective total hip arthroplasty (THA) or total knee arthroplasty (TKA) procedure for arthritis between April 2011 and March 2016 in Ontario. We made univariate comparisons between patients who presented to the emergency department within 30 days of surgery and those who did not in. We determined differences in use of health care services between groups by comparing the change in use in the year before and after surgery between patients who presented to the emergency department and those who did not. We developed logistic regression models for the occurrence of an emergency department visit using backward variable elimination.

RESULTS

We identified 42 273 total hip recipients and 70 725 total knee recipients, of whom 5640 (13.3%) and 11 224 (15.9%), respectively, presented to the emergency department within 30 days of surgery. Fewer than 1% of these patients required admission, and nearly half (45%) went to a different institution from where they had their surgery. Among both THA and TKA recipients, patients who presented to the emergency department had a net increase in their median annual health care costs (THA: $501, TKA: $682), compared to a net decrease for the cohort as a whole. Factors associated with increased risk of an emergency visit included increased patient age, male sex, rural residence and various comorbidities. Predictive regression models showed poor discriminative ability for both THA (C-statistic 0.57) and TKA (C-statistic 0.58) recipients.

INTERPRETATION

One in 7 patients presented to the emergency department within 30 days of THA or TKA. Some may conceivably have been managed remotely, and very few required readmission. There is a crucial need for strategies to minimize these events.

Deprivation status and the hospital costs of an emergency medical admission

BACKGROUND

Deprivation has been shown to adversely affect health outcomes. However, whether deprivation increases hospitalisation costs is uncertain. We have examined the relationship between deprivation and the costs of emergency medical admissions in a single centre between 2008-2014.

METHODS

We calculated the total hospital costs of emergency admissions related to their deprivation status, based on area of residence (Electoral Division - small census area). We used truncated Poisson and quantile regression methods to examine relationships between predictor variables and total hospital episode costs.

RESULTS

Over the study period, 29,508 episodes were recorded in 15,932 patients. Compared with the least deprived (Q1), the incidence rate ratios (IRR) for annual costs were increased to Q3 1.15 (95% CI: 1.12, 1.19), Q4 2.39 (95% CI: 2.30, 2.49) and Q5 2.76 (95% CI: 2.68, 2.85). The margin statistic cost estimate per thousand population increased from 183.8 K€ in Q1 to 507.9 K€ in Q5. The total bed days/1000 population increased as follows (compared with Q1): Q3 IRR 1.41 (95% CI: 1.37, 1.45), Q4 1.96 (95% CI: 1.89, 2.03) and Q5 3.04 (95% CI: 2.96, 3.12). The margin statistic bed day estimate (/1000 population) increased from 218.7 in Q1 to 664.0 in Q5.

CONCLUSION

Deprivation status had a profound impact on total hospital costs for emergency medical admissions. This was primarily mediated through a tripling of total bed days in the most deprived groups.

Outcomes of After-Hours Hip Fracture Surgery

BACKGROUND

Given single-institution studies showing trends between after-hours hip fracture surgical procedures and adverse outcomes, as well as fixation time targets that may increasingly compel after-hours operations, we investigated the relationship between after-hours hip fracture surgical procedures and adverse outcomes in a large, population-based cohort.

METHODS

All Ontarians who were ≥60 years of age and underwent a hip fracture surgical procedure between April 2002 and March 2014 were eligible for study inclusion. Data were obtained from linked health administrative databases. The primary exposure was after-hours provision of surgical procedures, occurring weekday evenings between the hours of 5 P.M. and 12 A.M. or over the weekend, but not overnight (after 12 A.M. to 7 A.M.). Surgical complications up to 6 months following a hip fracture surgical procedure comprised the primary outcome. Medical complications, including mortality, up to 90 days postoperatively were also assessed. Odds ratios (ORs) were calculated using a logistic regression model that accounted for clustering at the hospital level and adjusted for patient, provider, and fracture characteristics previously shown to explain the majority of variance in hip fracture outcomes.

RESULTS

During the study period, 87,647 patients underwent an isolated hip fracture surgical procedure; 51.2% of these patients had femoral neck fractures, 44.1% had intertrochanteric fractures, and 4.7% had subtrochanteric fractures. The surgical procedure occurred after hours in 59,562 patients (68.0%), and 27,240 patients (31.1%) underwent a surgical procedure during normal hours (7 A.M. to 5 P.M.). Only 845 patients (1%) underwent a surgical procedure overnight. We observed no significant relationships between timing of the surgical procedure and adverse outcomes, except for patients who had undergone an after-hours surgical procedure and had fewer inpatient surgical complications (OR, 0.90 [95% confidence interval, 0.83 to 0.99]; p = 0.01).

CONCLUSIONS

Adverse outcomes following a hip fracture surgical procedure were similar whether a surgical procedure occurred during normal hours or after hours. Concerns regarding the quality of after-hours surgical procedures should not influence hip fracture prioritization policy. However, given that the great majority of hip fracture surgical procedures occurred after hours, future research should examine other potential consequences of this practice, such as financial impact and surgeon burnout.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Factors associated with choosing the emergency department as the primary access point to health care: a Canadian population cross-sectional study

Objective

Approximately 4.3 million Canadians are without a primary care physician, of which 13% choose the emergency department (ED) as their regular access point to health care. We sought to identify factors associated with preferential ED use over other health services. We hypothesized that socioeconomic barriers (i.e., employment, health status, education) to primary care would also prevent access to ED alternatives.

Methods

Data from the Canadian Community Health Survey, 2007 to 2008, were analysed (N=134,073; response rate 93.5%). Our study population comprised 14,091 individuals identified without a primary care physician. Socioeconomic variables included employment, health, and education. Covariates included chronic health conditions, immigrant status, gender, age, and mental health. Prevalence estimates and 95% confidence intervals (CIs) for each variable were calculated. Weighted logistic regression models were constructed to evaluate the importance of individual risk factors and their interactions after adjustment for relevant covariates.

Results

The sample comprised 57.2% males from across Canada. Employment (OR 0.73 [95% CI: 0.59-0.90]), good health (OR 0.73 [95% CI 0.57-0.88]), and post-secondary education (OR 0.68 [95% CI 0.53-0.88]) reduced respondents use of the ED. The reduced odds of ED use were independent of chronic conditions, mental health, gender, poor mobility, province, and age.

Conclusions

Low socioeconomic status dictates preferential ED use in those without a primary care physician. Specific policy and system development targeting this at-risk population are indicated to alter ED use patterns in this population.

Socioeconomic composition of low-acuity emergency department users in Ontario

OBJECTIVE

To describe the associations between the socioeconomic status of emergency department (ED) users and age, sex, and acuity of medical conditions to better understand users' common characteristics, and to better meet primary and ambulatory health care needs.

DESIGN

A retrospective, observational, population-based analysis. A rigorous proxy of socioeconomic status was applied using census-based methods to calculate a relative deprivation index.

SETTING

Ontario.

PARTICIPANTS

All Ontario ED visits for the fiscal year April 1, 2008, to March 31, 2009, from the National Ambulatory Care Reporting System data set.

MAIN OUTCOME MEASURES

Emergency department visits were ranked into deprivation quintiles, and associations between deprivation and age, sex, acuity at triage, and association with a primary care physician were investigated.

RESULTS

More than 25% of ED visits in Ontario were from the most deprived population; almost half of those (12.3%) were for conditions of low acuity. Age profiles indicated that a large contribution to low-acuity ED visits was made by young adults (aged 20 to 30 years) from the most deprived population. For the highest-volume ED in Ontario, 94 of the 499 ED visits per day were for low-acuity patients from the most deprived population. Most of the highest volume EDs in Ontario (more than 200 ED visits per day) follow this trend.

CONCLUSION

Overall input into EDs might be reduced by providing accessible and appropriate primary health care resources in catchment areas of EDs with high rates of low-acuity ED visits, particularly for young adults from the most deprived segment of the population.

Neighbourhood characteristics, individual attributes and self-rated health among older Canadians

This study drew on three cycles of the Canadian Community Health Survey and the 2001 Census to examine between-neighbourhood variation in positive and negative self-rated health and the relative effect of individual and neighbourhood characteristics on self-rated health among Canadian adults aged > or = 65. Multilevel logistic regression results showed that there was modest, but significant between-neighbourhood variation in self-rated health. Neighbourhood factors including income, education, and percentage of people aged > or = 65, and visible minority accounted for about 50% and 30% of the neighbourhood variation in negative and positive self-rated health, respectively. Relative to neighbourhood-level characteristics, individual characteristics had a stronger effect on self-rated health with involvement in physical activity, alcohol consumption, sense of community belonging, income, and education being the most important. Although the findings suggest that neighbourhood effects on self-rated health are modest and that individual-level factors are relatively more important determinants of health, research concern for contextual influences on health should continue.

Socioeconomic status and utilization of health care services in Canada and the United States: findings from a binational health survey

OBJECTIVES

Building on Andersen's behavioral model for the utilization of health care services, we examined factors associated with utilization of physician and hospital services among adults in Canada and the United States, with a focus on socioeconomic status (enabling resources in Andersen's framework).

METHODS

Using the 2002-2003 Joint Canada/United States Survey of Health, we conducted country-specific multivariate logistic regressions predicting doctor contacts/visits and overnight hospitalizations in the past year, controlling for predisposing characteristics, enabling resources, and several factors representing perceived need for health care. All analyses were appropriately weighted to yield nationally representative results.

RESULTS

Several measures of socioeconomic status-having a regular medical doctor, education, and, in the US income and insurance coverage-were associated with doctor contacts or visits in both countries, along with various predisposing and need factors. However, these same measures were not associated with hospitalizations in either country. Instead, only the individual's predisposing characteristics (eg, age and sex) and his/her need for health care predicted utilization of hospital services in Canada and the United States. Insurance coverage status in the United States became a significant predictor of hospitalizations when count data were analyzed via Poisson regression.

CONCLUSIONS

Given our particular outcome measures, adults in Canada and the United States exhibited similar patterns of hospital utilization, and socioeconomic status played no explanatory role. However, relative to Canadian adults, we found disparities in doctor contacts among US adults-between those with more income and those with less, between those with health insurance and those without-after adjusting for health care needs and predisposing characteristics.

Appropriateness of hospitalization for CAP-affected pediatric patients: report from a Southern Italy General Hospital

Background

Community-acquired pneumonia (CAP) is a common disease, responsible for significant healthcare expenditures, mostly because of hospitalization. Many practice guidelines on CAP have been developed, including admission criteria, but a few on appropriate hospitalization in children. The aim of this study was to evaluate appropriate hospital admission for CAP in a pediatric population.

Methods

We evaluated appropriate admission to a Pediatric Unit performing a retrospective analysis on CAP admitted pediatric patients from a Southern Italy area. Diagnosis was made based on clinical and radiological signs. Appropriate hospital admission was evaluated following clinical and non-clinical international criteria. Family ability to care children was assessed by evaluating social deprivation status.

Results

In 2 winter seasons 120 pediatric patients aged 1-129 months were admitted because of CAP. Median age was 28.7 months. Raised body temperature was scored in 68.3% of patients, cough was present in 100% of cases, and abdominal pain was rarely evidenced. Inflammatory indices (ESR and CRP) were found elevated in 33.3% of cases. Anti-Mycoplasma pneumoniae antibodies were found positive in 20.4%. Trans-cutaneous (TC) SaO₂ was found lower than 92% in 14.6%. Dyspnoea was present in 43.3%. Dehydration requiring i.v. fluid supplementation was scored in 13.3%. Evaluation of familial ability to care their children revealed that 76% of families (derived from socially depressed areas) were "at social risk", thus not able to appropriately care their children. Furthermore, analysis of CAP patients revealed that "at social risk" people accessed E.D. and were hospitalized more frequently than "not at risk" patients (odds ratio = 3.59, 95% CI: 1,15 to 11,12; p = 0.01), and that admitted "at social risk" people presented without clinical signs of severity (namely dyspnoea, and/or SaO2 ≤ 92%, and/or dehydration) more frequently than "not at risk" population (p = 0.005).

Conclusion

Dyspnoea was found to be the main clinical criterion to define an appropriate children admission for CAP. Other more objective evaluation (i.e. oxygen pulse oxymetry) could underestimate the necessity of hospitalization as patients discomfort could be more severe then indicated by TC SaO2. Furthermore, family inability to children care represents the main criterion for hospital admission in our geographic area. It reflects social deprivation status and it should be strongly considered in deciding for children hospital admission.

Collaborative community-based teaching clinics at the Canadian Memorial Chiropractic College: addressing the needs of local poor communities

INTRODUCTION

Inequities in access to health services, resulting from cuts in public sector budgets and inflation, greatly affect Canada's poorest and most vulnerable people. The purpose of this article is to describe the experiences of the community-based teaching clinics of the Canadian Memorial Chiropractic College (CMCC), located in the poor, inner city region of Toronto, where access to chiropractic care for this population has been enabled.

DISCUSSION

Three chiropractic teaching clinics have been established in host facilities in the inner city community of Toronto. For over a decade, CMCC has had collaborative chiropractic clinics in the Sherbourne Health Centre (a southeast Toronto primary care facility), and Anishnawbe Health Toronto (an aboriginal health facility addressing the needs of urban First Nations people). For 3 years, we have been providing chiropractic services in the Department of Family and Community Medicine at St Michael's Hospital. The priority for these programs was the minimization of economic barriers to accessing care for poor and marginalized people. Outcomes have demonstrated high use when there is no economic barrier, excellent clinical outcomes and patient satisfaction, and a high level of collaboration with other health practitioners.

CONCLUSION

The CMCC's external clinics program has enabled access to chiropractic services to thousands of people living in the inner city and urban aboriginal communities of Toronto. This has resulted in the minimization of barriers to accessing care, the provision of appropriate and effective care, and collaboration. These clinics also greatly increase students' awareness of, sensitivity to, and commitment to being part of the solution to these problems.

The effect of homelessness on hospitalisation among patients with HIV/AIDS

The purpose of this study was to determine the effect of homelessness on the costs and patterns of hospitalisation in patients with HIV/AIDS. A retrospective longitudinal study design, based on medical records data covering 2,768 person-years of observation between 1997 and 2003 on patients with HIV/AIDS, was employed. A contextual measure of neighbourhood socioeconomic status (SES) was also used to uncover differences among low- and high-SES neighbourhood dwellers. The association of homelessness and neighbourhood SES with total annual hospitalisation costs, length of stay, numbers of hospital and emergency department admissions and the probability of an operating room procedure, controlling for other covariates, was assessed using multivariate regression analysis. Our results suggest that the homeless and low-SES neighbourhood residents had a large proportion of total costs attributable to admissions for acute events related to the progression of disease. Hospitalisations for planned operating room procedures comprised a relatively larger proportion of hospitalisation costs for high-SES neighbourhood residents. One implication of our findings is that improvements in the continuity of care and cost savings on inpatient care may be realised through further development of social assistance programs aimed at reaching the homeless and residents of low-SES neighbourhoods.

Socioeconomic status and hospital utilization among younger adult pneumonia admissions at a Canadian hospital

BACKGROUND

Although the general association between socioeconomic status (SES) and hospitalization has been well established, few studies have considered the relationship between SES and hospital length of stay (LOS), and/or hospital re-admission. The primary objective of this study therefore, was to examine the relationship of SES to LOS and early re-admission among adult patients hospitalized with community-acquired pneumonia in a setting with universal health insurance.

METHODS

Four hundred and thirty-four (434) individuals were included in this retrospective, longitudinal cohort analysis of adult patients less than 65 years old admitted to a large teaching hospital in Vancouver, British Columbia. Hospital chart review data were linked to population-based health plan administrative data. Chart review was used to gather data on demographics, illness severity, co-morbidity, functional status and other measures of case mix. Two different types of administrative data were used to determine hospital LOS and the occurrence of all-cause re-admission to any hospital within 30 days of discharge. SES was measured by individual-level financial hardship (receipt of income assistance or provincial disability pension) and neighbourhood-level income quintiles.

RESULTS

Those with individual-level financial hardship had an estimated 15% (95% CI -0.4%, +32%, p = 0.057) longer adjusted LOS and greater risk of early re-admission (adjusted OR 2.65, 95% CI 1.38, 5.09). Neighbourhood-level income quintiles, showed no association with LOS or early re-admission.

CONCLUSION

Among hospitalized pneumonia patients less than 65 years, financial hardship derived from individual-level data, was associated with an over two-fold greater risk of early re-admission and a marginally significant longer hospital LOS. However, the same association was not apparent when an ecological measure of SES derived from neighbourhood income quintiles was examined. The ecological SES variable, while useful in many circumstances, may lack the sensitivity to detect the full range of SES effects in clinical studies.

Low-income Canadians’ experiences with health-related services: Implications for health care reform

This study investigated the use of health-related services by low-income Canadians living in two large cities, Edmonton and Toronto. Interview data collected from low-income people, service providers and managers, advocacy group representatives, and senior-level public servants were analyzed using thematic content analysis. Findings indicate that, in addition to health care policies and programs, a broad range of policies, programs, and services relating to income security, recreation, and housing influence the ability of low-income Canadians to attain, maintain, and enhance their health. Furthermore, the manner in which health-related services are delivered plays a key role in low-income people's service-use decisions. We conclude the paper with a discussion of the health and social policy implications of the findings, which are particularly relevant within the context of recent health care reform discussions in Canada.

Experiencing difficulties accessing first-contact health services in Canada: Canadians without regular doctors and recent immigrants have difficulties accessing first-contact healthcare services. Reports of difficulties in accessing care vary by age, sex and region

In this study, we identify the significant factors associated with having difficulties accessing first-contact healthcare services. Population-based data from two national health surveys, the Health Services Access Survey and the Canadian Community Health Survey, were used to identify respondents who required first-contact services for themselves or for a family member during 2003. Fifteen percent of Canadians reported difficulty accessing routine care, and 23% reported difficulties with immediate care. Physician/service availability was the chief reason cited for difficulties accessing routine care, while for urgent care, it was long wait times. Women, younger respondents and residents of eastern Canada and Quebec were consistently more likely to report difficulties accessing both types of these first-contact services, whereas less educated Canadians were less likely to report problems. Canadians without a regular family doctor were more than twice as likely to report difficulties accessing routine care compared to those who had a regular doctor. New immigrants were almost two and a half times more likely to report difficulties accessing immediate care than were Canadian-born respondents. Household income was not associated with difficulties accessing either type of care. The relatively low level of reporting of difficulties by older and less educated Canadians may be related, in part, to more modest expectations about the healthcare system.

Meeting health need, accessing health care: the role of neighbourhood

Much of what we know about the determinants of access to health care comes from studies undertaken at a large scale, such as between cities, regions/counties/provinces/states and countries. This paper examines local level variations in access to and utilization of health care services across four distinct neighbourhoods in Hamilton, Ontario, Canada. Survey data (n = 1500) were analysed using logistic regression to explore the potential relationships between neighbourhood and health care utilization and unmet health care need. Results show some relationships between neighbourhood of residence and levels of reported utilization as well as unmet need, even when controlling for predisposing, enabling, and need factors (i.e. Age, gender, household composition, income, education, perceived gp visit time) as well as health status. Findings from this empirical study suggest a finer lens is required to examine the mechanisms through which place impacts access to and utilization of care, one that recognizes the roles of compositional, contextual and collective aspects of neighbourhood.

To what extent does poor health precede welfare?

BACKGROUND

It is well known that individuals receiving social assistance have more health problems than those with higher incomes. In this paper, we estimate the proportion of social assistance recipients who were on welfare following a drop in health status.

METHODS

The study population consisted of Saskatchewan adults who had been continuously off social assistance for 12 consecutive months followed by 6 months on social assistance. Health status was measured by the use of physician services. We examined changes in physician service rates during the 18-month period.

RESULTS

Forty-nine percent of individuals in the study population had increases in the number of physician services over the 18-month period. For these individuals, 53% of the increase in service use occurred during the 12 months prior to receiving social assistance.

CONCLUSIONS

Deteriorating health, as measured by increased physician service use, seems to be one factor that precedes many people's receipt of welfare. A focus on improving health status may be one way to keep people off welfare.

'Reasonable access' to primary care: assessing the role of individual and system characteristics

Access to health care continues to be an important issue for health policy makers, researchers, service providers and consumers alike. In countries with universal health care coverage, services are generally free at the point of delivery which is intended to provide equitable access to care for all residents regardless of their individual situations. Past studies have pointed to the importance of individual characteristics such as age, gender, and socioeconomic status in shaping access to health care but much less is known about the role of health system characteristics. The purpose of this study is to explore, by means of qualitative research methods, the extent to which individual and system factors shape access to primary health care services for residents living in two contrasting neighbourhoods in Hamilton, Ont., Canada. Semi-structured, in-depth interviews were conducted with 40 men and women. The interviews probed participants about their experiences with primary care, barriers to receiving care and their general perceptions of the health care system. The interviews demonstrated the existence of many system-related barriers to receiving health care (e.g., wait times, geographic inaccessibility and quality of care) and some individual-related barriers (e.g., work or family responsibilities). While the findings revealed little difference between the neighbourhoods in terms of accessibility problems and barriers, differences between men and women were evident.

Neighbourhood recent immigration and hospitalization in Toronto, Canada

Recent immigrants to Canada tend to initially settle in low-income urban core areas. The relationships among immigration, neighbourhood effects and health are poorly understood. This study explored the risk of hospitalization in high recent-immigration areas in Toronto compared to other Toronto neighbourhoods. The study used 1996 hospitalization and census data. Regression was used to examine the effects of recent immigration on neighbourhood hospitalization rates. Most hospitalization categories showed significantly higher rates of admission as the proportion of recent immigrants increased. Income was also significantly associated with all categories of hospitalization except surgical admissions. Average household income was almost 60% lower (dollar 36,122) in the highest versus the lowest immigration areas (dollar 82,641) suggesting that, at the neighbourhood level, the effects of immigration and income may be difficult to disentangle. These findings have important implications for health care planning, delivery, and policy.

Evaluation of a community-based inner-city disease management program for postmyocardial infarction patients: a randomized controlled trial

BACKGROUND

Disease management programs (DMPs) that use multidisciplinary teams and specialized clinics reduce hospital admissions and improve quality of life and functional status. Evaluations of cardiac DMPs delivered by home health nurses are required.

METHODS

Between August 1999 and August 2000 we identified consecutive patients admitted to hospital with elevated cardiac enzymes. Patients who agreed were randomly assigned to participate in a DMP or to receive usual care. The DMP included 6 home visits by a cardiac-trained nurse, a standardized nurses' checklist, referral criteria for specialty care, communication with the family physician and patient education. We measured readmission days per 1000 follow-up days for angina, congestive heart failure (CHF) and chronic obstructive pulmonary disease (COPD); all-cause readmission days; and provincial claims for emergency department visits, physician visits, diagnostic or therapeutic services and laboratory services.

RESULTS

We screened 715 consecutive patients admitted with elevated cardiac markers between August 1999 and August 2000. Of those screened 71 DMP and 75 usual care patients met the diagnostic criteria for myocardial infarction, were eligible for visits from a home health nurse and consented to participate in the study. Readmission days for angina, CHF and COPD per 1000 follow-up days were significantly higher for usual care patients than for DMP patients (incidence density ratio [IDR] = 1.59, 95% confidence interval [CI] 1.27-2.00, p < 0.001). All-cause readmission days per 1000 follow-up days were significantly higher for usual care patients than for DMP patients (IDR = 1.53, 95% CI 1.37-1.71, p < 0.001). The difference in emergency department encounters per 1000 follow-up days was significant (IDR = 2.08, 95% CI 1.56-2.77, p < 0.001). During the first 25 days after discharge, there were significantly fewer provincial claims submitted for DMP patients than for usual care patients for emergency department visits (p = 0.007), diagnostic or therapeutic services (p = 0.012) and laboratory services (p = 0.007).

INTERPRETATION

The results provide evidence that an appropriately developed and implemented community-based inner-city DMP delivered by home health nurses has a positive impact on patient outcomes.

Predictors of early hospital readmission in HIV-infected patients with pneumonia

OBJECTIVE

Although hospitalization patterns have been studied, little is known about hospital readmission among HIV-infected patients in the era of highly active antiretroviral therapy. We explored the risk factors for early readmission to a tertiary care inner-city hospital among HIV-infected patients with pneumonia in Vancouver, Canada.

DESIGN

Case-control study.

SETTING

Tertiary care, university-affiliated, inner-city hospital.

PARTICIPANTS

All HIV-infected patients who were hospitalized with Pneumocystis carinii pneumonia (PCP) or bacterial pneumonia (BP) between January 1997 and December 2000. Case patients included those who had early readmissions, defined as being readmitted within 2 weeks of discharge (N = 131). Control patients were randomly selected HIV-infected patients admitted during the study period who were not readmitted within 2 weeks of discharge (N = 131), matched to the cases by proportion of PCP to BP.

MEASUREMENTS

Sociodemographic, HIV risk category, and clinical data were compared using chi2 test for categorical variables, and the Wilcoxon rank-sum test was used for continuous variables. Multivariable logistic regression was performed to determine the factors independently associated with early readmission. We also reviewed the medical records of 132 patients admitted to the HIV/AIDS ward during the study period and collected more detailed clinical data for a subanalysis.

MAIN RESULTS

Patients were at significantly increased odds of early readmission if they left the hospital against medical advice (AMA) (adjusted odds ratio [OR], 4.26; 95% confidence interval [95% CI], 2.13 to 8.55), lived in the poorest urban neighborhood (OR, 2.03; 95% CI, 1.09 to 3.77), were hospitalized in summer season (May though October, OR, 2.36; 95% CI, 1.36 to 4.10), or had been admitted in the preceding 6 months (OR, 2.55; 95% CI, 1.46 to 4.47). Gender, age, history of AIDS-defining illness, and injection drug use status were not significantly associated with early readmission.

CONCLUSIONS

Predictors of early readmission of HIV-infected patients with pneumonia included: leaving hospital AMA, living in the poorest urban neighborhood, being hospitalized in the preceding 6 months and during the summer months. Interventions involving social work may address some of the underlying reasons why these patients leave hospital AMA and should be further studied.

Misclassification of income quintiles derived from area-based measures. A comparison of enumeration area and forward sortation area

BACKGROUND

Census-based methods are often used to estimate socioeconomic status. We assessed the agreement between Forward Sortation Area (FSA) and Enumeration Area (EA) derived income levels for all patients undergoing cardiac catheterization in Alberta, Canada, from 1995-1998.

METHODS

Income quintiles were calculated from census data for FSA and EA level. FSA- and EA-derived income measures were compared for misclassification. Both methods were then applied to the data to determine 4-year survival by income grouping in 21,446 patients following catheterization.

RESULTS

The variability in EA-derived incomes for any given FSA-derived income is large. Only 40% of income quintiles are in agreement between the methods. For EA-based analyses, there is a linear relationship between higher income and lower mortality across all quintiles, while for FSA-based analyses, only the lowest income quintile had significantly higher mortality.

DISCUSSION

Assuming that FSA-based methods are more likely to misclassify income compared to EA-based measures, the results for the FSA-based analyses are more likely to be erroneous. EA-derived measures should therefore be used when individual data are not available.

Misclassification of income quintiles derived from area-based measures. A comparison of enumeration area and forward sortation area

BACKGROUND

Census-based methods are often used to estimate socioeconomic status. We assessed the agreement between Forward Sortation Area (FSA) and Enumeration Area (EA) derived income levels for all patients undergoing cardiac catheterization in Alberta, Canada, from 1995-1998.

METHODS

Income quintiles were calculated from census data for FSA and EA level. FSA- and EA-derived income measures were compared for misclassification. Both methods were then applied to the data to determine 4-year survival by income grouping in 21,446 patients following catheterization.

RESULTS

The variability in EA-derived incomes for any given FSA-derived income is large. Only 40% of income quintiles are in agreement between the methods. For EA-based analyses, there is a linear relationship between higher income and lower mortality across all quintiles, while for FSA-based analyses, only the lowest income quintile had significantly higher mortality.

DISCUSSION

Assuming that FSA-based methods are more likely to misclassify income compared to EA-based measures, the results for the FSA-based analyses are more likely to be erroneous. EA-derived measures should therefore be used when individual data are not available.

Individual and neighbourhood determinants of health care utilization. Implications for health policy and resource allocation

OBJECTIVES

To investigate the importance of both individual and neighbourhood socioeconomic characteristics for health care utilization.

METHODS

Various linkage procedures generated a longitudinal dataset with information on 2,116 Nova Scotians, their residential neighbourhoods, 8 years of health care utilization and vital status. Unilevel and multilevel regression analyses were employed to examine the effects of both individual and neighbourhood characteristics on health care use.

RESULTS

Individual income and education determined physician and hospital use. Also, neighbourhood characteristics, specifically average income and percentage of single mother families, were found to determine health care use. When considering individual and neighbourhood characteristics simultaneously, individual income and education determined physician and hospital use independently, while neighbourhood income determined physician use independently.

CONCLUSIONS

Both individual and neighbourhood socioeconomic characteristics determine health care use. Acknowledging this allows better targeting of health policy and planning, and enables more accurate needs-based resource allocation.

Individual and neighbourhood determinants of health care utilization. Implications for health policy and resource allocation

OBJECTIVES

To investigate the importance of both individual and neighbourhood socioeconomic characteristics for health care utilization.

METHODS

Various linkage procedures generated a longitudinal dataset with information on 2,116 Nova Scotians, their residential neighbourhoods, 8 years of health care utilization and vital status. Unilevel and multilevel regression analyses were employed to examine the effects of both individual and neighbourhood characteristics on health care use.

RESULTS

Individual income and education determined physician and hospital use. Also, neighbourhood characteristics, specifically average income and percentage of single mother families, were found to determine health care use. When considering individual and neighbourhood characteristics simultaneously, individual income and education determined physician and hospital use independently, while neighbourhood income determined physician use independently.

CONCLUSIONS

Both individual and neighbourhood socioeconomic characteristics determine health care use. Acknowledging this allows better targeting of health policy and planning, and enables more accurate needs-based resource allocation.

Hospital utilization and costs in a cohort of injection drug users

BACKGROUND

Many injection drug users (IDUs) seek care at emergency departments and some require hospital admission because of late presentation in the course of their illness. We determined the predictors of frequent emergency department visits and hospital admissions among community-based IDUs and estimated the incremental hospital utilization costs incurred by IDUs with early HIV infection relative to costs incurred by HIV-negative IDUs.

METHODS

The Vancouver Injection Drug User Study (VIDUS) is a prospective cohort study involving IDUs that began in 1996. Our analyses were restricted to the 598 participants who gave informed consent for our study. We used the participants' responses to the baseline VIDUS questionnaire and, from medical records at St. Paul's Hospital, Vancouver, we collected detailed information about the frequency of emergency department visits, hospital admissions and the primary diagnosis for all visits or hospital stays between May 1, 1996, and Aug. 31, 1999. The incremental difference in hospital utilization costs by HIV status was estimated, based on 105 admissions in a subgroup of 64 participants.

RESULTS

A total of 440 (73.6%) of the 598 IDUs made 2763 visits to the emergency department at St. Paul's Hospital during the study period. Of these 440, 265 (160.2%) made frequent visits (3 or more). The following factors were associated with frequent use: HIV-positive status (seroprevalent: adjusted odds ratio [OR] 1.7, 95% confidence interval [CI] 1.2-2.6; seroconverted during study period: adjusted OR 3.0, 95% CI 1.6-5.7); more than 4 injections daily (adjusted OR 1.5, 95% CI 1.1-2.1); cocaine use more frequent than use of other drugs (adjusted OR 2.0, 95% CI 1.2-3.6); and unstable housing (adjusted OR 1.5, 95% CI 1.1-2.2). During the study period 210 of the participants were admitted to hospital 495 times; 118 (56.2%) of them were admitted frequently (2 or more admissions). The 2 most common reasons for admission were pneumonia (132 admissions among 79 patients) and soft-tissue infections (cellulitis and skin abscess) (90 admissions among 59 patients). The following factors were independently associated with frequent hospital admissions: HIV-positive status (seroprevalent: adjusted OR 5.4, 95% CI 3.4-8.6; seroconverted during study period: adjusted OR 2.9, 95% CI 1.4-6.0); and female sex (adjusted OR 1.8, 95% CI 1.1-3.1). The incremental hospital utilization costs incurred by HIV-positive IDUs relative to the costs incurred by HIV-negative IDUs were $1752 per year.

INTERPRETATION

Hospital utilization was significantly higher among community-based IDUs with early HIV disease than among those who were HIV negative. Much of the hospital use was related to complications of injection drug use and may be reduced with the establishment of programs that integrate harm reduction strategies with primary care and addiction treatment.