Predictive performance of comorbidity measures in administrative databases for diabetes cohorts

Sex-Based Disparities in Acute Myocardial Infarction Treatment Patterns and Outcomes in Older Adults Hospitalized Across 6 High-Income Countries: An Analysis From the International Health Systems Research Collaborative

BACKGROUND

Sex differences in acute myocardial infarction treatment and outcomes are well documented, but it is unclear whether differences are consistent across countries. The objective of this study was to investigate the epidemiology, use of interventional procedures, and outcomes for older females and males hospitalized with ST-segment-elevation myocardial infarction (STEMI) and non-ST-segment-elevation myocardial infarction (NSTEMI) in 6 diverse countries.

METHODS

We conducted a serial cross-sectional cohort study of 1 508 205 adults aged ≥66 years hospitalized with STEMI and NSTEMI between 2011 and 2018 in the United States, Canada, England, the Netherlands, Taiwan, and Israel using administrative data. We compared females and males within each country with respect to age-standardized hospitalization rates, rates of cardiac catheterization, percutaneous coronary intervention, and coronary artery bypass graft surgery within 90 days of hospitalization, and 30-day age- and comorbidity-adjusted mortality.

RESULTS

Hospitalization rates for STEMI and NSTEMI decreased between 2011 and 2018 in all countries, although the hospitalization rate ratio (rate in males/rate in females) increased in virtually all countries (eg, US STEMI ratio, 1.58:1 in 2011 and 1.73:1 in 2018; Israel NSTEMI ratio, 1.71:1 in 2011 and 2.11:1 in 2018). Rates of cardiac catheterization, percutaneous coronary intervention, and coronary artery bypass graft surgery were lower for females than males for STEMI in all countries and years (eg, US cardiac catheterization in 2018, 88.6% for females versus 91.5% for males; Israel percutaneous coronary intervention in 2018, 76.7% for females versus 84.8% for males) with similar findings for NSTEMI. Adjusted mortality for STEMI in 2018 was higher for females than males in 5 countries (the United States, Canada, the Netherlands, Israel, and Taiwan) but lower for females than males in 5 countries for NSTEMI.

CONCLUSIONS

We observed a larger decline in acute myocardial infarction hospitalizations for females than males between 2011 and 2018. Females were less likely to receive cardiac interventions and had higher mortality after STEMI. Sex disparities seem to transcend borders, raising questions about the underlying causes and remedies.

Effect of the Implementation of the French Hospital Regionalization Policy on Patient Mobility

A new law was voted in France in 2016 to increase cooperation between public sector hospitals. Hospitals were encouraged to work under the leadership of local referral centers and to share their support functions (e.g., information systems) with newly created hospital groups, called "Regional Hospital Groups." The law made it compulsory for each public sector hospital to become affiliated with one of 136 newly created hospital groups. The policy's aim was to ensure that all patients were sent to the hospital best qualified to treat their unique condition, among the hospitals available at the regional level. Therefore, we aimed to assess whether this regionalization policy was associated with changes in observed patterns of patient mobility between hospitals. This nationwide observational study followed an interrupted time series design. For each stay occurring from 2014 to 2019, we ascertained whether or not the stay was followed by mobility toward another hospital within 90 days, and whether or not the receiving hospital was part of the same Regional Hospital Group as the sender hospital. The proportion of mobility directed toward the same regional hospital group increased from 22.9% in 2014 (95% CI 22.7-23.1) to 24.6% in 2019 (95% CI 24.4-24.8). However, the absence of discontinuity during the policy change year was consistent with the hypothesis of a preexisting trend toward regionalization. Therefore, the policy did not achieve major changes in patterns of mobility between hospitals. Other objectives of the reform, including long-term consequences on the healthcare offer, remain to be assessed.

Differences in Treatment Patterns and Outcomes of Acute Myocardial Infarction for Low- and High-Income Patients in 6 Countries

Importance

Differences in the organization and financing of health systems may produce more or less equitable outcomes for advantaged vs disadvantaged populations. We compared treatments and outcomes of older high- and low-income patients across 6 countries.

Objective

To determine whether treatment patterns and outcomes for patients presenting with acute myocardial infarction differ for low- vs high-income individuals across 6 countries.

Design, Setting, and Participants

Serial cross-sectional cohort study of all adults aged 66 years or older hospitalized with acute myocardial infarction from 2013 through 2018 in the US, Canada, England, the Netherlands, Taiwan, and Israel using population-representative administrative data.

Exposures

Being in the top and bottom quintile of income within and across countries.

Main Outcomes and Measures

Thirty-day and 1-year mortality; secondary outcomes included rates of cardiac catheterization and revascularization, length of stay, and readmission rates.

Results

We studied 289 376 patients hospitalized with ST-segment elevation myocardial infarction (STEMI) and 843 046 hospitalized with non-STEMI (NSTEMI). Adjusted 30-day mortality generally was 1 to 3 percentage points lower for high-income patients. For instance, 30-day mortality among patients admitted with STEMI in the Netherlands was 10.2% for those with high income vs 13.1% for those with low income (difference, -2.8 percentage points [95% CI, -4.1 to -1.5]). One-year mortality differences for STEMI were even larger than 30-day mortality, with the highest difference in Israel (16.2% vs 25.3%; difference, -9.1 percentage points [95% CI, -16.7 to -1.6]). In all countries, rates of cardiac catheterization and percutaneous coronary intervention were higher among high- vs low-income populations, with absolute differences ranging from 1 to 6 percentage points (eg, 73.6% vs 67.4%; difference, 6.1 percentage points [95% CI, 1.2 to 11.0] for percutaneous intervention in England for STEMI). Rates of coronary artery bypass graft surgery for patients with STEMI in low- vs high-income strata were similar but for NSTEMI were generally 1 to 2 percentage points higher among high-income patients (eg, 12.5% vs 11.0% in the US; difference, 1.5 percentage points [95% CI, 1.3 to 1.8 ]). Thirty-day readmission rates generally also were 1 to 3 percentage points lower and hospital length of stay generally was 0.2 to 0.5 days shorter for high-income patients.

Conclusions and Relevance

High-income individuals had substantially better survival and were more likely to receive lifesaving revascularization and had shorter hospital lengths of stay and fewer readmissions across almost all countries. Our results suggest that income-based disparities were present even in countries with universal health insurance and robust social safety net systems.

Fractures and long-term mortality in cancer patients: a population-based cohort study

We assessed post-fracture mortality in a population-based cohort of 122,045 individuals with cancers. Major fractures (hip, vertebrae, humerus, and forearm) were associated with early and long-term increased all-cause mortality.

INTRODUCTION

Currently, there are no population-based data among cancer patients on post-fracture mortality risk across a broad range of cancer diagnoses. Our objective was to estimate the association of fracture with mortality in cancer survivors.

METHODS

Using Manitoba Cancer Registry data from the province of Manitoba, Canada, we identified all women and men with cancer diagnosed between January 1, 1987, and March 31, 2014. We then linked cancer data to provincial healthcare administrative data and ascertained fractures after cancer diagnosis and mortality to March 31, 2015. Hazard ratios for all-cause mortality in those with versus without fracture were estimated from time-dependent Cox proportional hazards models adjusted for multiple covariates.

RESULTS

The study cohort consisted of 122,045 cancer patients (median age 68 years, IQR 58-77, 49.2% female). During the median follow-up of 5.8 years from cancer diagnosis, we ascertained 7120 (5.8%) major fractures. All fracture sites, except for the forearm, were associated with increased mortality risk, even after multivariable adjustment. Excess mortality risk associated with a major fracture was greatest in the first year after fracture (HR 2.42, 95% CI 2.30-2.54) and remained significant > 5 years after fracture (HR 1.60, 95% CI 1.50-1.70) and for fractures occurring > 10 years after cancer diagnosis (HR 1.93, 95% CI 1.79-2.07).

CONCLUSION

Fractures among cancer patients are associated with increased all-cause mortality. This excess risk is greatest in the first year and persists more than 5 years post-fracture; increased risk is also noted for fractures occurring up to and beyond 10 years after cancer diagnosis.

Health service use before and after dementia diagnosis: a retrospective matched case-control study

OBJECTIVES

This study investigated patterns in health service usage among older adults with dementia and matched controls over a 10-year span from 5 years before until 5 years after diagnosis.

DESIGN

Population-based retrospective matched case-control study.

SETTING

Administrative health data of individuals in Saskatchewan, Canada from 1 April 2008 to 31 March 2019.

PARTICIPANTS

The study included 2024 adults aged 65 years and older living in the community at the time of dementia diagnosis from 1 April 2013 to 31 March 2014, matched 1:1 to individuals without a dementia diagnosis on age group, sex, rural versus urban residence, geographical region and comorbidity.

OUTCOME MEASURES

For each 5-year period before and after diagnosis, we examined usage of health services each year including family physician (FP) visits, specialist visits, hospital admissions, all-type prescription drug dispensations and short-term care admissions. We used negative binomial regression to estimate the effect of dementia on yearly average health service utilisation adjusting for sex, age group, rural versus urban residence, geographical region, 1 year prior health service use and comorbidity.

RESULTS

Adjusted findings demonstrated that 5 years before diagnosis, usage of all health services except hospitalisation was lower among persons with dementia than persons without dementia (all p<0.001). After this point, differences in higher health service usage among persons with dementia compared to without dementia were greatest in the year before and year after diagnosis. In the year before diagnosis, specialist visits were 59.7% higher (p<0.001) and hospitalisations 90.5% higher (p<0.001). In the year after diagnosis, FP visits were 70.0% higher (p<0.001) and all-type drug prescriptions 29.1% higher (p<0.001).

CONCLUSIONS

Findings suggest the year before and year after diagnosis offer multiple opportunities to implement quality supports. FPs are integral to dementia care and require effective resources to properly serve this population.

Data Quality of Automated Comorbidity Lists in Patients With Mental Health and Substance Use Disorders

EHRs provide an opportunity to conduct research on underrepresented oncology populations with mental health and substance use disorders. However, a lack of data quality may introduce unintended bias into EHR data. The objective of this article is describe our analysis of data quality within automated comorbidity lists commonly found in EHRs. Investigators conducted a retrospective chart review of 395 oncology patients from a safety-net integrated healthcare system. Statistical analysis included κ coefficients and a condition logistic regression. Subjects were racially and ethnically diverse and predominantly used Medicaid insurance. Weak κ coefficients ( κ = 0.2-0.39, P < .01) were noted for drug and alcohol use disorders indicating deficiencies in comorbidity documentation within the automated comorbidity list. Further, conditional logistic regression analyses revealed deficiencies in comorbidity documentation in patients with drug use disorders (odds ratio, 11.03; 95% confidence interval, 2.71-44.9; P = .01) and psychoses (odds ratio, 0.04; confidence interval, 0.02-0.10; P < .01). Findings suggest deficiencies in automatic comorbidity lists as compared with a review of provider narrative notes when identifying comorbidities. As healthcare systems increasingly use EHR data in clinical studies and decision making, the quality of healthcare delivery and clinical research may be affected by discrepancies in the documentation of comorbidities.

Quality criteria/key components for high quality of diabetes management to avoid diabetes-related complications

Aim

The aim of this review shoud be to map data and to identify quality indicators for good practices for diabetes management and secondary prevention, specifically of type 2 diabetes.

Methods

To achieve this aim we performed the following steps: (i) a literature review on evaluation criteria, (ii) selection of quality criteria and key components for high quality of care, (iii) creation of a checklist to identify the best practice of diabetes management based on the detected criteria.

Results

The literature search about the quality indicators for diabetes care resulted in the following: identifying of key components and quality indicators for structure, process and outcome quality.

Conclusions

The set of quality criteria will be discussed and used to identify the best practice diabetes management programs for secondary prevention of type 2 diabetes.

Comparative Performance of Comorbidity Measures in Predicting Health Outcomes in Patients with Chronic Obstructive Pulmonary Disease

Purpose

Multiple studies have suggested that comorbidities pose negative impacts on the survival of patients with chronic obstructive pulmonary disease (COPD); few have applied comorbidity measures driven from health insurance claims databases to predict various health outcomes. We aimed to examine the performance of commonly used comorbidity measures based on diagnosis and pharmacy dispensing claims information in predicting future death and hospitalization in COPD patients.

Methods

We identified COPD patients in a population-based Taiwanese database. We built logistic regression models with age, sex, and baseline comorbidities measured by either diagnosis or pharmacy claims information as predictors of subsequent-year death or hospitalization in a random 50% sample and validated the discrimination in the other 50%. The diagnosis-based comorbidity measures included the Charlson Index and the Elixhauser comorbidity measure; the pharmacy-based comorbidity measures included the updated Chronic Disease Score (CDS) and the Pharmacy-Based Comorbidity Index (PBDI).

Results

We identified 428,251 eligible patients. For overall death, the Elixhauser comorbidity measure showed the best predictive performance (c-statistic=0.832), followed by the PBDI (c-statistic=0.822), the Charlson Index (c-statistic=0.815), and the updated CDS (c-statistic=0.808). For overall hospitalization, the PBDI (c-statistics=0.730) and the Elixhauser comorbidity measure (c-statistics=0.724) outperformed the updated CDS (c-statistics=0.714) and the Charlson Index (c-statistics=0.710). For hospitalization due to cardiovascular, cerebrovascular, or respiratory diseases, the comorbidity models showed similar predictive ranks and demonstrated c-statistics higher than 0.75. However, none of the models could adequately predict hospitalization due to other reasons (c-statistics < 0.60).

Conclusion

Our study comprehensively compared the predictive performance of comorbidity measures. The Elixhauser comorbidity measure and the PBDI are useful tools for describing comorbid conditions and predicting health outcomes in COPD patients.

Risk factors for infection, revision, death, blood transfusion and longer hospital stay 3 months and 1 year after primary total hip or knee arthroplasty

BACKGROUND

Total joint replacement (TJR) is increasingly performed in older patients with more comorbidities, who are considered at higher risk for postoperative complications. We aimed to identify and calculate the odds ratio of the risk factors for infection, revision and death 3 months and 1 year after TJR as well as for postoperative blood transfusion and longer hospital stay.

METHODS

We analyzed all primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) cases in Nova Scotia between Apr. 1, 2000, and Mar. 31, 2014, as identified from the Discharge Abstract Database. We used the Charlson Comorbidity Index as a surrogate measure of comorbidities. We used hospital and physician billings data and Nova Scotia Vital Statistics data to identify the postoperative events in this cohort.

RESULTS

A total of 10 123 primary THA and 17 243 primary TKA procedures were performed during the study period. The mean patient age was 66.1 (standard deviation 11.7) years and 67.1 (standard deviation 9.3) years, respectively. With THA, the risk of infection was higher in patients with heart failure and those with diabetes. For TKA, liver disease and blood transfusion were associated with a higher risk of infection. Revision rates were higher among patients with hypertension and those with paraparesis/hemiparesis for THA, and among patients with metastatic disease for TKA. Significant risk factors for death included metastatic disease, older age, heart failure, myocardial infarction, dementia, rheumatologic disease, renal disease, blood transfusion and cancer. Multiple medical comorbidities and older age were associated with higher rates of blood transfusion and longer hospital stay.

CONCLUSION

We have identified the risk factors associated with higher rates of postoperative complications and longer hospital stay after TJR. The results enable individualized risk stratification during the preoperative consultation.

The effect of socio-demographic factors on mental health and addiction high-cost use: a retrospective, population-based study in Saskatchewan

OBJECTIVE

A small proportion of the population accounts for the majority of healthcare costs. Mental health and addiction (MHA) patients are consistently high-cost. We aimed to delineate factors amenable to public health action that may reduce high-cost use among a cohort of MHA clients in Saskatoon, Saskatchewan.

METHODS

We conducted a population-based retrospective cohort study. Administrative health data from fiscal years (FY) 2009-2015, linked at the individual level, were analyzed (n = 129,932). The outcome of interest was ≥ 90th percentile of costs for each year under study ('persistent high-cost use'). Descriptive analyses were followed by logistic regression modelling; the latter excluded long-term care residents.

RESULTS

The average healthcare cost among study cohort members in FY 2009 was ~ $2300; for high-cost users it was ~ $19,000. Individuals with unstable housing and hospitalization(s) had increased risk of persistent high-cost use; both of these effects were more pronounced as comorbidities increased. Patients with schizophrenia, particularly those under 50 years old, had increased probability of persistent high-cost use. The probability of persistent high-cost use decreased with good connection to a primary care provider; this effect was more pronounced as the number of mental health conditions increased.

CONCLUSION

Despite constituting only 5% of the study cohort, persistent high-cost MHA clients (n = 6455) accounted for ~ 35% of total costs. Efforts to reduce high-cost use should focus on reduction of multimorbidity, connection to a primary care provider (particularly for those with more than one MHA), young patients with schizophrenia, and adequately addressing housing stability.

Changes in healthcare use among individuals who move into public housing: a population-based investigation

Background

Residence in public housing, a subsidized and managed government program, may affect health and healthcare utilization. We compared healthcare use in the year before individuals moved into public housing with usage during their first year of tenancy. We also described trends in use.

Methods

We used linked population-based administrative data housed in the Population Research Data Repository at the Manitoba Centre for Health Policy. The cohort consisted of individuals who moved into public housing in 2009 and 2010. We counted the number of hospitalizations, general practitioner (GP) visits, specialist visits, emergency department visits, and prescriptions drugs dispensed in the twelve 30-day intervals (i.e., months) immediately preceding and following the public housing move-in date. Generalized linear models with generalized estimating equations tested for a period (pre/post-move-in) by month interaction. Odds ratios (ORs), incident rate ratios (IRRs), and means are reported along with 95% confidence intervals (95% CIs).

Results

The cohort included 1942 individuals; the majority were female (73.4%) who lived in low income areas and received government assistance (68.1%). On average, the cohort had more than four health conditions. Over the 24 30-day intervals, the percentage of the cohort that visited a GP, specialist, and an emergency department ranged between 37.0% and 43.0%, 10.0% and 14.0%, and 6.0% and 10.0%, respectively, while the percentage of the cohort hospitalized ranged from 1.0% to 5.0%. Generally, these percentages were highest in the few months before the move-in date and lowest in the few months after the move-in date. The period by month interaction was statistically significant for hospitalizations, GP visits, and prescription drug use. The average change in the odds, rate, or mean was smaller in the post-move-in period than in the pre-move-in period.

Conclusions

Use of some healthcare services declined after people moved into public housing; however, the decrease was only observed in the first few months and utilization rebounded. Knowledge of healthcare trends before individuals move in are informative for ensuring the appropriate supports are available to new public housing residents. Further study is needed to determine if decreased healthcare utilization following a move is attributable to decreased access.

Electronic supplementary material

The online version of this article (10.1186/s12913-018-3109-7) contains supplementary material, which is available to authorized users.

Association of Evidence-Based Care Processes With Mortality in Staphylococcus aureus Bacteremia at Veterans Health Administration Hospitals, 2003-2014

IMPORTANCE

Staphylococcus aureus bacteremia is common and frequently associated with poor outcomes. Evidence indicates that specific care processes are associated with improved outcomes for patients with S aureus bacteremia, including appropriate antibiotic prescribing, use of echocardiography to identify endocarditis, and consultation with infectious diseases (ID) specialists. Whether use of these care processes has increased in routine care for S aureus bacteremia or whether use of these processes has led to large-scale improvements in survival is unknown.

OBJECTIVE

To examine the association of evidence-based care processes in routine care for S aureus bacteremia with mortality.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective observational cohort study examined all patients admitted to Veterans Health Administration (VHA) acute care hospitals who had a first episode of S aureus bacteremia from January 1, 2003, through December 31, 2014.

EXPOSURES

Use of appropriate antibiotic therapy, echocardiography, and ID consultation.

MAIN OUTCOMES AND MEASURES

Thirty-day all-cause mortality.

RESULTS

Analyses included 36 868 patients in 124 hospitals (mean [SD] age, 66.4 [12.5] years; 36 036 [97.7%] male), including 19 325 (52.4%) with infection due to methicillin-resistant S aureus and 17 543 (47.6%) with infection due to methicillin-susceptible S aureus. Risk-adjusted mortality decreased from 23.5% (95% CI, 23.3%-23.8%) in 2003 to 18.2% (95% CI, 17.9%-18.5%) in 2014. Rates of appropriate antibiotic prescribing increased from 2467 (66.4%) to 1991 (78.9%), echocardiography from 1256 (33.8%) to 1837 (72.8%), and ID consultation from 1390 (37.4%) to 1717 (68.0%). After adjustment for patient characteristics, cohort year, and other care processes, receipt of care processes was associated with lower mortality, with adjusted odds ratios of 0.74 (95% CI, 0.68-0.79) for appropriate antibiotics, 0.73 (95% CI, 0.68-0.78) for echocardiography, and 0.61 (95% CI, 0.56-0.65) for ID consultation. Mortality decreased progressively as the number of care processes that a patient received increased (adjusted odds ratio for all 3 processes compared with none, 0.33; 95% CI, 0.30-0.36). An estimated 57.3% (95% CI, 48.4%-69.9%) of the decrease in mortality between 2003 and 2014 could be attributed to increased use of these evidence-based care processes.

CONCLUSIONS AND RELEVANCE

Mortality associated with S aureus bacteremia decreased significantly in VHA hospitals, and a substantial portion of the decreasing mortality may have been attributable to increased use of evidence-based care processes. The experience in VHA hospitals demonstrates that increasing application of these care processes may improve survival among patients with S aureus bacteremia in routine health care settings.

Comorbidity and its relationship with health service use and cost in community-living older adults with diabetes: A population-based study in Ontario, Canada

AIMS

This study describes the comorbid conditions in Canadian, community-dwelling older adults with diabetes and the association between the number of comorbidities and health service use and costs.

METHODS

This retrospective cohort study used multiple linked administrative data to determine 5-year health service utilization in a population-based cohort of community-living individuals aged 66 and over with a diabetes diagnosis as of April 1, 2008 (baseline). Utilization included physician visits, emergency department visits, hospitalizations, and home care services.

RESULTS

There were 376,421 cohort members at baseline, almost all (95%) of which had at least one comorbidity and half (46%) had 3 or more. The most common comorbidities were hypertension (83%) and arthritis (61%). Service use and associated costs consistently increased as the number of comorbidities increased across all services and follow-up years. Conditions generally regarded as nondiabetes-related were the main driver of service use. Over time, use of most services declined for people with the highest level of comorbidity (3+). Hospitalizations and emergency department visits represented the largest share of costs for those with the highest level of comorbidity (3+), whereas physician visits were the main costs for those with fewer comorbidities.

CONCLUSIONS

Comorbidities in community-living older adults with diabetes are common and associated with a high level of health service use and costs. Accordingly, it is important to use a multiple chronic conditions (not single-disease) framework to develop coordinated, comprehensive and patient-centred programs for older adults with diabetes so that all their needs are incorporated into care planning.

Variation in the Intensity of Care for Patients with Uncomplicated Renal Colic Presenting to U.S. Emergency Departments

BACKGROUND

Renal colic results in > 1 million ED visits per year, yet there exists a gap in understanding how the majority of these visits, namely uncomplicated cases, are managed.

OBJECTIVE

We assessed patient- and hospital-level variation for emergency department (ED) management of uncomplicated kidney stones.

METHODS

We identified ED visits from non-elderly adults (aged 19-79 years) with a primary diagnosis indicating renal stone or colic from the 2011 Nationwide Emergency Department Sample. Patients with additional diagnostic codes indicating infection, sepsis, and abdominal aortic aneurysm were excluded. We used sample-weighted logistic regression to determine the association between hospital admission and having a urologic procedure with patient and hospital characteristics.

RESULTS

Of the 1,061,462 ED visits for uncomplicated kidney stones in 2011, 8.0% of visits resulted in admission and 6.3% resulted in an inpatient urologic procedure. Uninsured patients compared to Medicaid insured patients were less likely to be admitted or have an inpatient urologic procedure (odds ratio [OR] = 0.72; 95% confidence interval [CI] 0.65-0.81 and OR = 0.80; 95% CI 0.72-0.87, respectively). Private- and Medicare-insured patients compared to Medicaid-insured patients were more likely to have an inpatient urologic procedure (OR = 1.20; 95% CI 1.11-1.30 and OR = 1.14; 95% CI 1.04-1.25, respectively).

CONCLUSIONS

For patients with uncomplicated renal colic, there is variation in the management associated with nonclinical factors, namely insurance. No consensus guidelines exist yet to address when to admit or utilize inpatient urologic procedures.

Modification of claims-based measures improves identification of comorbidities in non-elderly women undergoing mastectomy for breast cancer: a retrospective cohort study

Background

Accurate identification of underlying health conditions is important to fully adjust for confounders in studies using insurer claims data. Our objective was to evaluate the ability of four modifications to a standard claims-based measure to estimate the prevalence of select comorbid conditions compared with national prevalence estimates.

Methods

In a cohort of 11,973 privately insured women aged 18–64 years with mastectomy from 1/04–12/11 in the HealthCore Integrated Research Database, we identified diabetes, hypertension, deficiency anemia, smoking, and obesity from inpatient and outpatient claims for the year prior to surgery using four different algorithms. The standard comorbidity measure was compared to revised algorithms which included outpatient medications for diabetes, hypertension and smoking; an expanded timeframe encompassing the mastectomy admission; and an adjusted time interval and number of required outpatient claims. A χ2 test of proportions was used to compare prevalence estimates for 5 conditions in the mastectomy population to national health survey datasets (Behavioral Risk Factor Surveillance System and the National Health and Nutrition Examination Survey). Medical record review was conducted for a sample of women to validate the identification of smoking and obesity.

Results

Compared to the standard claims algorithm, use of the modified algorithms increased prevalence from 4.79 to 6.79 % for diabetes, 14.75 to 24.87 % for hypertension, 4.23 to 6.65 % for deficiency anemia, 1.78 to 12.87 % for smoking, and 1.14 to 6.31 % for obesity. The revised estimates were more similar, but not statistically equivalent, to nationally reported prevalence estimates. Medical record review revealed low sensitivity (17.86 %) to capture obesity in the claims, moderate negative predictive value (NPV, 71.78 %) and high specificity (99.15 %) and positive predictive value (PPV, 90.91 %); the claims algorithm for current smoking had relatively low sensitivity (62.50 %) and PPV (50.00 %), but high specificity (92.19 %) and NPV (95.16 %).

Conclusions

Modifications to a standard comorbidity measure resulted in prevalence estimates that were closer to expected estimates for non-elderly women than the standard measure. Adjustment of the standard claims algorithm to identify underlying comorbid conditions should be considered depending on the specific conditions and the patient population studied.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-016-1636-7) contains supplementary material, which is available to authorized users.

Health and social predictors of applications to public housing: a population-based analysis

BACKGROUND

Residents of public housing are often in poor health. However, it is unclear whether poor health precedes residency in public housing. We compared the health of people who applied to public housing to people who did not apply and had similar socioeconomic characteristics.

METHODS

Population-based administrative databases from Manitoba, Canada, containing health, housing and income assistance information were used to identify a cohort of individuals who applied to public housing and a matched cohort from the general population. Conditional logistic regression was used to test the association between a public housing application and health status and health service use, after controlling for income.

RESULTS

There were 10 324 individuals in each of the public housing applicant and matched cohorts; the majority were women, young, urban residents, and received income assistance. A higher per cent of the public housing cohort had physician-diagnosed physical and mental health conditions compared to the matched cohort. Physical health, mental health and health service use were significantly associated with applying to public housing, after controlling for individual and area-level income.

CONCLUSIONS

Applicants to public housing were in poorer health compared to people of the same income level who did not apply to public housing. These health issues may affect the long-term stability of their tenancy if appropriate services and supports are not provided. Additionally, preventing ill health, better management of mental health and additional supports may reduce the need for public housing, which, in turn, would alleviate the pressure on governments to provide this form of housing.

New ICD-10 version of the Multipurpose Australian Comorbidity Scoring System outperformed Charlson and Elixhauser comorbidities in an older population

OBJECTIVES

To translate, validate, and compare performance of an International Classification of Diseases, 10th revision (ICD-10) version of the Multipurpose Australian Comorbidity Scoring System (MACSS) against commonly used comorbidity measures in the prediction of short- and long-term mortality, 28-day all-cause readmission, and length of stay (LOS).

STUDY DESIGN AND SETTING

Hospitalization and death data were linked for 25,374 New South Wales residents aged 65 years and older, admitted with a hip fracture between 2008 and 2012. Comorbidities were identified according to the MACSS, Charlson, and Elixhauser definitions using ICD-10 coding algorithms. Regression models were fitted and area under the curve (AUC) and Akaike Information Criterion assessed.

RESULTS

The ICD-10 MACSS had excellent discriminating ability in predicting inhospital mortality (AUC = 0.81) and 30-day mortality (AUC = 0.80), acceptable prediction of 1-year mortality (AUC = 0.76) but poor discrimination for 28-day readmission and LOS. The MACSS algorithm provided better model fit than either Charlson or Elixhauser algorithm for all outcomes.

CONCLUSION

This work presents a rigorous translation of the ICD-9 MACSS for use with ICD-10 coded data. The updated ICD-10 MACSS outperformed both Charlson and Elixhauser measures in an older population and is recommended for use with large administrative data sets in predicting mortality outcomes.

Formal Professional Relationships Between General Practitioners and Specialists in Shared Care: Possible Associations with Patient Health and Pharmacy Costs

BACKGROUND

Shared care in chronic disease management aims at improving service delivery and patient outcomes, and reducing healthcare costs. The introduction of shared-care models is coupled with mixed evidence in relation to both patient health status and cost of care. Professional interactions among health providers are critical to a successful and efficient shared-care model.

OBJECTIVE

This article investigates whether the strength of formal professional relationships between general practitioners (GPs) and specialists (SPs) in shared care affects either the health status of patients or their pharmacy costs. In strong GP-SP relationships, the patient health status is expected to be high, due to efficient care coordination, and the pharmacy costs low, due to effective use of resources.

METHODS

This article measures the strength of formal professional relationships between GPs and SPs through the number of shared patients and proxies the patient health status by the number of comorbidities diagnosed and treated. To test the hypotheses and compare the characteristics of the strongest GP-SP connections with those of the weakest, this article concentrates on diabetes-a chronic condition where patient care coordination is likely important. Diabetes generates the largest shared patient cohort in Hungary, with the highest frequency of specialist medication prescriptions.

RESULTS

This article finds that stronger ties result in lower pharmacy costs, but not in higher patient health status.

CONCLUSION

Overall drug expenditure may be reduced by lowering patient care fragmentation through channelling a GP's patients to a small number of SPs.

Estimating the prevalence of comorbid conditions and their effect on health care costs in patients with diabetes mellitus in Switzerland

BACKGROUND

Estimating the prevalence of comorbidities and their associated costs in patients with diabetes is fundamental to optimizing health care management. This study assesses the prevalence and health care costs of comorbid conditions among patients with diabetes compared with patients without diabetes. Distinguishing potentially diabetes- and nondiabetes-related comorbidities in patients with diabetes, we also determined the most frequent chronic conditions and estimated their effect on costs across different health care settings in Switzerland.

METHODS

Using health care claims data from 2011, we calculated the prevalence and average health care costs of comorbidities among patients with and without diabetes in inpatient and outpatient settings. Patients with diabetes and comorbid conditions were identified using pharmacy-based cost groups. Generalized linear models with negative binomial distribution were used to analyze the effect of comorbidities on health care costs.

RESULTS

A total of 932,612 persons, including 50,751 patients with diabetes, were enrolled. The most frequent potentially diabetes- and nondiabetes-related comorbidities in patients older than 64 years were cardiovascular diseases (91%), rheumatologic conditions (55%), and hyperlipidemia (53%). The mean total health care costs for diabetes patients varied substantially by comorbidity status (US$3,203-$14,223). Patients with diabetes and more than two comorbidities incurred US$10,584 higher total costs than patients without comorbidity. Costs were significantly higher in patients with diabetes and comorbid cardiovascular disease (US$4,788), hyperlipidemia (US$2,163), hyperacidity disorders (US$8,753), and pain (US$8,324) compared with in those without the given disease.

CONCLUSION

Comorbidities in patients with diabetes are highly prevalent and have substantial consequences for medical expenditures. Interestingly, hyperacidity disorders and pain were the most costly conditions. Our findings highlight the importance of developing strategies that meet the needs of patients with diabetes and comorbidities. Integrated diabetes care such as used in the Chronic Care Model may represent a useful strategy.