Patterns of multiple chronic conditions in pregnancy: Population-based study using latent class analysis.

BACKGROUND: Adults with multiple chronic conditions (MCC) are a heterogeneous population with elevated risk of future adverse health outcomes. Yet, despite the increasing prevalence of MCC globally, data about MCC in pregnancy are scarce. OBJECTIVES: To estimate the population prevalence of MCC in pregnancy and determine whether certain types of chronic conditions cluster together among pregnant women with MCC. METHODS: We conducted a population-based cohort study in Ontario, Canada, of all 15-55-year-old women with a recognised pregnancy, from 2007 to 2020. MCC was assessed from a list of 22 conditions, identified using validated algorithms. We estimated the prevalence of MCC. Next, we used latent class analysis to identify classes of co-occurring chronic conditions in women with MCC, with model selection based on parsimony, clinical interpretability and statistical fit. RESULTS: Among 2,014,508 pregnancies, 324,735 had MCC (161.2 per 1000, 95% confidence interval [CI] 160.6, 161.8). Latent class analysis resulted in a five-class solution. In four classes, mood and anxiety disorders were prominent and clustered with one additional condition, as follows: Class 1 (22.4% of women with MCC), osteoarthritis; Class 2 (23.7%), obesity; Class 3 (15.8%), substance use disorders; and Class 4 (22.1%), asthma. In Class 5 (16.1%), four physical conditions clustered together: obesity, asthma, chronic hypertension and diabetes mellitus. CONCLUSIONS: MCC is common in pregnancy, with sub-types dominated by co-occurring mental and physical health conditions. These data show the importance of preconception and perinatal interventions, particularly integrated care strategies, to optimise treatment and stabilisation of chronic conditions in women with MCC.

Risk of Repeat Psychiatric Emergency Department Visits in the Postpartum Period: A Population-Based Retrospective Cohort Study.

STUDY OBJECTIVE: Approximately 1 in 100 postpartum individuals visit an emergency department (ED) for a psychiatric reason. Repeat visits can signify problems with the quality of care received during or after the initial visit; this study aimed to understand risk for repeat postpartum psychiatric ED visits. METHODS: This population-based cohort study used Ontario, Canada health administrative data available through ICES (formerly the Institute for Clinical Evaluative Sciences) to identify all individuals discharged from postpartum psychiatric ED visits (2008 to 2021) and measured the proportion with one or more repeat psychiatric ED visit within 30 days. Using modified Poisson regression, we calculated the association between one or more repeat visits and sociodemographic, medical, obstetric, infant, continuity of care, past service use, and index ED visit characteristics both overall and stratified by psychiatric diagnosis. RESULTS: Of 14,100 individuals, 11.7% had one or more repeat psychiatric ED visits within 30 days. Repeat visit risk was highest for those with schizophrenia-spectrum disorders (28.2%, adjusted risk ratio 2.41; 95% confidence interval 1.88 to 3.08, versus 9.5% anxiety referent). Low (versus no) psychiatric care continuity, prior psychiatric ED visits and admissions, and initial visits within 90 days postpartum were also associated with increased risk, whereas intentional self-injury was associated with reduced risk. In diagnosis-stratified analyses, the factors most consistently associated with repeat ED visits were past psychiatric ED visits and admissions, and initial visits within 90 days postpartum. CONCLUSIONS: Over 1 in 10 postpartum psychiatric ED visits are followed by a repeat visit within 30 days. Targeted approaches are needed across clinical populations to reduce repeat ED visits in this population with young infants.

Association between dermatology follow-up and melanoma survival: A population-based cohort study.

BACKGROUND: Guidelines recommend that patients with melanoma undergo dermatologic examination at least annually. Adherence to follow-up and its impact on survival are unclear. OBJECTIVE: To determine the level of adherence to annual dermatologic follow-up in patients with primary cutaneous melanoma, identify predictors for better adherence, and evaluate whether adherence was associated with melanoma-related mortality. METHODS: Retrospective inception cohort analysis of adults with primary invasive melanoma in Ontario, Canada from 2010 to 2013 with follow-up until December 31, 2018. RESULTS: Adherence to dermatologic follow-up was variable with only 28.0% of patients seeing a dermatologist at least annually (median follow-up 5.0 years). Younger age, female sex, higher income, greater access to dermatology care, stage 2/3 melanoma, prior keratinocyte carcinoma, fewer comorbidities, and any outpatient visit in the 12 months prior to melanoma diagnosis were predictors for adherence. Greater adherence to annual dermatology visits was associated with reduced melanoma-specific mortality compared with lower levels of adherence (adjusted hazard ratio 0.64, 95% CI 0.52-0.78). LIMITATIONS: Observational study design and inability to identify skin examinations performed by non-dermatologists. CONCLUSION: Adherence to annual dermatology visits after melanoma diagnosis was low. Greater adherence may promote better patient survival but warrants confirmation in further research including randomized trials.

Mental Illness in the 2 Years Prior to Pregnancy in a Population With Traumatic Brain Injury: A Cross-Sectional Study: La maladie mentale dans les deux ans précédant une grossesse dans une population souffrant de lésion cérébrale traumatique : une étude transversale.

OBJECTIVE: Existing studies, in mostly male samples such as veterans and athletes, show a strong association between traumatic brain injury (TBI) and mental illness. Yet, while an understanding of mental health before pregnancy is critical for informing preconception and perinatal supports, there are no data on the prevalence of active mental illness before pregnancy in females with TBI. We examined the prevalence of active mental illness ≤2 years before pregnancy (1) in a population with TBI, and (2) in subgroups defined by sociodemographic, health, and injury-related characteristics, all compared to those without TBI. METHOD: This population-based cross-sectional study was completed in Ontario, Canada, from 2012 to 2020. Modified Poisson regression generated adjusted prevalence ratios (aPRs) of active mental illness ≤2 years before pregnancy in 15,585 females with TBI versus 846,686 without TBI. We then used latent class analysis to identify subgroups with TBI according to sociodemographic, health, and injury-related characteristics and subsequently compared them to females without TBI on their outcome prevalence. RESULTS: Females with TBI had a higher prevalence of active mental illness ≤2 years before pregnancy than those without TBI (44.1% vs. 25.9%; aPR 1.46, 95% confidence interval, 1.43 to 1.49). There were 3 TBI subgroups, with Class 1 (low-income, past assault, recent TBI described as intentional and due to being struck by/against) having the highest outcome prevalence. CONCLUSIONS: Females with TBI, and especially those with a recent intentional TBI, have a high prevalence of mental illness before pregnancy. They may benefit from mental health screening and support in the post-injury, preconception, and perinatal periods. PLAIN LANGUAGE TITLE: Mental illness in the 2 years before pregnancy in a population with traumatic brain injury. PLAIN LANGUAGE SUMMARY: Research has shown a strong association between traumatic brain injury (TBI) and mental illness. Most previous studies have been conducted in primarily male samples, like veterans and professional athletes. Understanding mental health before pregnancy is important for deciding what supports people need before and during pregnancy. However, there are no studies on the frequency of mental illness in females with TBI before a pregnancy. We examined the frequency of mental illness 2 years before pregnancy in a population with TBI, and in subgroups defined by different social, health, and injury-related characteristics, compared to those without TBI. We undertook a population-wide study of all females with and without TBI in Ontario, Canada, with a birth in 2012-2020. We used statistical models to compare these groups on the presence of mental illness in the 2 years before pregnancy, before and after accounting for social and health characteristics. We also identified subgroups with TBI according to their social (e.g., poverty), health (e.g., chronic conditions), and injury-related characteristics (e.g., cause of injury) and subsequently compared them to females without TBI on their frequency of mental illness in the 2 years before pregnancy. Forty-four percent of females with TBI had mental illness in the 2 years before pregnancy compared to 25% of those without TBI. There were 3 TBI subgroups. Females with low-income, past assault, and injuries that were described as being intentional had the highest frequency of mental illness in the 2 years before pregnancy. Females with TBI may benefit from mental health screening and support post-injury and around the time of pregnancy.

The Mortality Risk of Proton Pump Inhibitors in 1.9 Million US Seniors: An Extended Cox Survival Analysis.

BACKGROUND & AIMS: Observational studies have linked proton pump inhibitors (PPIs) with increased risk of mortality and other safety outcomes, in contradiction with a recent PPI randomized controlled trial (RCT). Observational studies may be prone to reverse causality, where deaths are attributed to the treatment rather than the conditions that are treated (protopathic bias). METHODS: We analyzed an incident drug user cohort of 1,930,728 elderly Medicare fee-for-service beneficiaries to evaluate the PPI-associated risk of death with a Cox regression analysis with time-varying covariates and propensity score adjustments. To correct for protopathic bias which occurs when a given drug is associated with prodromal signs of death, we implemented a lag-time approach by which any study drug taken during a 90-day look-back window before each death was disregarded. RESULTS: Among 1,930,728 study individuals, 80,972 (4.2%) died during a median 3.8 years of follow-up, yielding an overall unadjusted death rate/1000 person-years of 9.85; 14.31 for PPI users and 7.93 for non- users. With no lag-time, PPI use (vs no use) was associated with 10% increased mortality risk (adjusted HR=1.10; 95% CI 1.08-1.12). However, with a lag-time of 90 days, mortality risk associated with PPI use was near zero (adjusted HR=1.01; 95% CI 0.99-1.02). CONCLUSION: Given the usage patterns of PPIs in patients with conditions that may presage death, protopathic bias may explain the association of PPIs with increased risk of death reported in observational studies.

Perinatal mental illness among women with disabilities: a population-based cohort study.

PURPOSE: To examine the risk of perinatal mental illness, including new-onset disorders and recurrent or ongoing use of mental health care, comparing women with physical, sensory, intellectual/developmental, and multiple disabilities to those without a disability. METHODS: From all women aged 15-49 years with a singleton birth in Ontario, Canada (2003-2018), those with physical (n = 144,972), sensory (n = 45,249), intellectual/developmental (n = 2,227), and ≥ 2 of these disabilities ("multiple disabilities"; n = 8,883), were compared to 1,601,363 without a disability on risk of healthcare system contact for mental illness from conception to 365 days postpartum. The cohort was stratified into: (1) no pre-pregnancy mental illness (to identify new-onset illness), (2) distal mental illness (> 2 years pre-pregnancy, to identify recurrent illness), and (3) recent mental illness (0-2 years pre-pregnancy, to identify ongoing contact). Modified Poisson regression generated relative risks (aRR), adjusted for age, parity, income quintile, and rural residence. RESULTS: About 14.7, 26.5, and 56.6% of women with no disabilities had new-onset, recurrent, and ongoing contact for mental illness, respectively, perinatally. Risks were elevated across disability groups for new-onset (physical: aRR 1.18, 95% CI 1.16-1.20; sensory: 1.11, 1.08-1.15; intellectual/developmental: 1.38, 1.17-1.62; multiple: 1.24, 1.15-1.33), recurrent (physical: 1.10, 1.08-1.12; sensory 1.06, 1.02-1.09; intellectual/developmental: 1.24, 1.11-1.37; multiple: 1.16, 1.09-1.23), and ongoing contact (physical: 1.09, 1.08-1.10; sensory: 1.08, 1.06-1.10; intellectual/developmental: 1.31, 1.26-1.37; multiple: 1.20, 1.16-1.23). CONCLUSION: The heightened use of new, recurrent, and ongoing mental health care across disability groups in the perinatal period suggests that adapted screening and intervention approaches are critical to optimize perinatal mental health in this population.

Incidence and mortality rates of keratinocyte carcinoma from 1998-2017: a population-based study of sex differences in Ontario, Canada.

BACKGROUND: Keratinocyte carcinoma is the most common malignant disease, but it is not captured in major registries. We aimed to describe differences by sex in the incidence and mortality rates of keratinocyte carcinoma in Ontario, Canada. METHODS: We conducted a population-based retrospective study of adults residing in Ontario between Jan. 1, 1998, and Dec. 31, 2017, using linked health administrative databases. We identified the first diagnosis of keratinocyte carcinoma using a validated algorithm of health insurance claims, and deaths related to keratinocyte carcinoma from death certificates. We calculated the incidence and mortality rates of keratinocyte carcinoma, stratified by sex, age and income quintile. We evaluated trends using the average annual percentage change (AAPC) based on joinpoint regression. RESULTS: After decreasing from 1998 to 2003, the incidence rate of keratinocyte carcinoma increased by 30% to 369 per 100 000 males and 345 per 100 000 females in 2017 (AAPC 1.9%, 95% confidence interval [CI] 1.7 to 2.1 from 2003 to 2017). The incidence rate was higher in females younger than 55 years, but higher in males aged 55 years or older. Between 2008 and 2017, the incidence rate rose faster in females than males aged 45-54 years (AAPC 1.2% v. 0.5%, p = 0.01) and 55-64 years (1.2% v. 0.1%, p < 0.01). The incidence was higher in males than females in the higher income quintiles. Between 1998 and 2017, the mortality rate of keratinocyte carcinoma was 1.8 times higher in males than females, on average, and rose 4.8-fold overall (AAPC 8.9%, 95% CI 6.4 to 11.4 in males; 8.0%, 95% CI 5.3-10.8 in females). INTERPRETATION: The population burden of keratinocyte carcinoma is growing, and the incidence and mortality rates rose disproportionately among certain sex- and age-specific groups. This warrants further investigation into causal factors and renewed preventive public health measures.

Postpartum mental illness during the COVID-19 pandemic: a population-based, repeated cross-sectional study.

BACKGROUND: It is unclear whether the clinical burden of postpartum mental illness has increased during the COVID-19 pandemic. We sought to compare physician visit rates for postpartum mental illness in Ontario, Canada, during the pandemic with rates expected based on prepandemic patterns. METHODS: In this population-based, repeated cross-sectional study using linked health administrative databases in Ontario, Canada, we used negative binomial regression to model expected visit rates per 1000 postpartum people for March-November 2020 based on prepandemic data (January 2016-February 2020). We compared observed visit rates to expected visit rates for each month of the pandemic period, generating absolute rate differences, incidence rate ratios (IRRs) and their 95% confidence intervals (CIs). The primary outcome was a visit to a primary care physician or a psychiatrist for any mental disorder. We stratified analyses by maternal sociodemographic characteristics. RESULTS: In March 2020, the visit rate was 43.5/1000, with a rate difference of 3.11/1000 (95% CI 1.25-4.89) and an IRR of 1.08 (95% CI 1.03-1.13) compared with the expected rate. In April, the rate difference (10.9/1000, 95% CI 9.14-12.6) and IRR (1.30, 95% CI 1.24-1.36) were higher; this level was generally sustained through November 2020. From April-November, we observed elevated visit rates across provider types and for diagnoses of anxiety, depressive and alcohol or substance use disorders. Observed increases from expected visit rates were greater for people 0-90 days postpartum compared with 91-365 days postpartum; increases were small among people living in low-income neighbourhoods. Public health units in the northern areas of the province did not see sustained elevations in visit rates after July; southern health units had elevated rates through to November. INTERPRETATION: Increased visits for mental health conditions among postpartum people during the first 9 months of the COVID-19 pandemic suggest an increased need for effective and accessible mental health care for this population as the pandemic progresses.

Risk of Mortality in Immigrants with Multiple Sclerosis in Ontario, Canada.

INTRODUCTION: Little is known about how mortality in multiple sclerosis (MS) may differ based on sociodemographic factors, such as immigrant status. We compared mortality in immigrants versus long-term residents with MS in Ontario, Canada. METHODS: In this retrospective cohort study, we applied a validated algorithm to linked, population-based immigration and health administrative data to identify incident MS cases in Ontario between 1994 and 2014. We identified date of death, if it occurred. We used a Cox model adjusting for age, sex, income, and comorbidity, to compare survival in immigrants versus long-term residents. RESULTS: There were 23,603 incident MS cases of whom 1,410 (6.0%) were immigrants. After adjusting for covariates, risk of death was higher in immigrants in the first year after diagnosis (hazard ratio [HR] 1.66; 95% CI 1.05-2.63, p = 0.031). However, in years 1-5 (HR 0.63; 95% CI 0.40-0.98, p = 0.041) and 5-10 (HR 0.42; 95% CI 0.24-0.75, p = 0.003) after diagnosis, risk of death was lower in immigrants. Older age at onset and comorbidity were associated with higher mortality; female sex and higher socioeconomic status were associated with lower mortality. CONCLUSIONS: In this large population with universal access to health care, immigrants with MS had higher mortality compared to long-term residents in the first year after onset and lower mortality thereafter. Lower mortality in immigrants to Canada is well described and thought to be due to the healthy immigrant effect. Higher mortality in the first year after MS onset warrants further investigation as some early deaths may be preventable.

Melanoma incidence, stage, and survival after solid organ transplant: A population-based cohort study in Ontario, Canada.

BACKGROUND: Risk of melanoma is increased with potentially worse outcomes after solid organ transplant. OBJECTIVE: To estimate the incidence, stage, and survival in transplant recipients with melanoma. METHODS: Population-based, retrospective, observational study using linked administrative databases. Adults receiving their first solid organ transplant from 1991 through 2012 were followed to December 2013. RESULTS: We identified 51 transplant recipients with melanoma, 11 369 recipients without melanoma, and 255 matched patients with melanoma from the nontransplant population. Transplant recipients were at increased risk of melanoma (standardized incidence ratio, 2.29; 95% confidence interval [CI], 2.07-2.49) and more likely to be diagnosed at stages II through IV (adjusted odds ratio, 4.29; 95% CI, 2.04-9.00) compared with the nontransplant population. Melanoma-specific mortality was increased in transplant recipients compared with the nontransplant population (adjusted hazard ratio, 1.93; 95% CI, 1.03-3.63). Among transplant recipients, all-cause mortality was increased after melanoma compared with those without melanoma (stage T1/T2: adjusted hazard ratio, 2.18; 95% CI, 1.13-4.21; T3/T4: adjusted hazard ratio, 4.07; 95% CI, 2.36-7.04; III/IV: adjusted hazard ratio, 7.92; 95% CI, 3.76-16.70). LIMITATIONS: The databases did not contain data on immunosuppressive drugs; ascertainment of melanoma metastasis relied on pathology reports. CONCLUSION: Melanoma after solid organ transplant is more often diagnosed at a later stage and leads to increased mortality, even for early-stage tumors.

Maternal schizophrenia and adverse birth outcomes: what mediates the risk?

PURPOSE: Maternal schizophrenia is associated with adverse birth outcomes, but the reasons for this remain unclear. In a population-based cohort of infants born to women with schizophrenia, we determined the occurrence of key perinatal outcomes and explored whether factors identifiable in our datasets explained any elevated risk. METHODS: Using population-level health administrative data linked to clinical birth-registry data in Ontario, Canada (2006-2011), we examined the relative risk (RR) of preterm birth (< 37 weeks), small for gestational age (SGA), and Apgar scores < 8 in infants of women with schizophrenia (n = 4279) versus infants of unaffected women (n = 286,147). Generalized estimating equations determined whether reproductive history, maternal health conditions, pregnancy exposures, and complications explained elevated RRs. RESULTS: Among infants of women with schizophrenia, risk was higher for prematurity (11.4% vs. 6.9%, aRR 1.64, 95% CI 1.51-1.79), SGA (3.5% vs. 2.5%, aRR 1.40, 95% CI 1.20-1.64), and Apgar score < 8 at 1 (19.0% vs. 12.8%, aRR 1.49, 95% CI 1.40-1.59) and 5 min (5.6% vs. 3.0%, aRR 1.90, 95% CI 1.68-2.16). Smoking, fourfold more common among women with schizophrenia, was the variable that explained the greatest proportion of the elevated aRR for prematurity (9.9%), SGA (28.7%), and Apgar < 8 at 1 and 5 min (9.8%, 5.6%). Illicit substance use, certain reproductive history variables, and pregnancy complications also contributed to the elevated aRR for preterm birth. CONCLUSIONS: Elevated risks of preterm birth, SGA, and low Apgar scores in infants of women with schizophrenia are partly explained by potentially modifiable factors such as smoking and illicit drug use, suggesting opportunities for targeted intervention.

Association between traumatic brain injury and prison charges: a population-based cohort study.

BACKGROUND: Traumatic Brain Injury (TBI) is a serious hidden health issue disproportionately affecting people who experience incarceration. OBJECTIVE: We examined the association between TBI and serious disciplinary charges among men and women sentenced by the courts to terms of two or more years. METHODS: The study originated in Ontario, Canada and used linked administrative health and correctional data. The cohort included adults experiencing their first federal sentence between 1998 and 2011 (N = 12,038). We examined disciplinary charges incurred 2 years post-sentence commencement. TBI was defined using the International Classification of Diseases (ICD-9 and ICD-10) diagnostic codes. Robust Poisson regression was conducted to assess the association between TBI and disciplinary charges. FINDINGS: The prevalence of TBI for the full sample was 13.2%. One-third of adults with a recent TBI had a serious disciplinary charge. The unadjusted risk of incurring a serious charge for those with a history of TBI was 39% higher than those with no history of TBI (CI: 1.29-1.49). The adjusted risk was 1.14 (CI: 1.06-1.22). CONCLUSIONS: TBI is a serious health concern that makes it difficult for incarcerants to adjust to prison. Additional support/resources are needed to support those with histories of TBI.

Development and validation of a multivariable prediction model for major adverse cardiovascular events after early stage breast cancer: a population-based cohort study.

AIMS: Develop a score to predict the risk of major adverse cardiovascular events (MACE) after early stage breast cancer (EBC) to facilitate personalized decision-making about potentially cardiotoxic treatments and interventions to reduce cardiovascular risk. METHODS AND RESULTS: Using administrative databases, we assembled a cohort of women diagnosed with EBC in Ontario between 2003 and 2014, with follow-up through 2015. Two-thirds of the cohort were used for risk score derivation; the remainder were reserved for its validation. The outcome was a composite of hospitalizations for acute myocardial infarction, unstable angina, transient ischaemic attack, stroke, peripheral vascular disease, heart failure (HF), or cardiovascular death. We developed the score by regressing MACE incidence against candidate predictors in the derivation sample using a Fine-Gray model. Discrimination was assessed in the validation sample using Wolber's c-index for prognostic models with competing risks, while calibration was assessed by comparing predicted and observed MACE incidence. The risk score was derived in 60 294 women and validated in 29 810 women. Age, hypertension, diabetes, ischaemic heart disease, atrial fibrillation, HF, cerebrovascular disease, peripheral vascular disease, chronic obstructive pulmonary disease, and chronic kidney disease were significantly associated with MACE incidence and incorporated into the score. Ten-year MACE incidence was >40-fold higher for patients in the highest score decile compared to the lowest. The c-index was 81.9% (95% confidence interval 80.9-82.9%) at 5 years and 79.8% (78.8-80.8%) at 10 years in the validation cohort, with good agreement between predicted and observed MACE incidence. CONCLUSION: Cardiovascular prognosis after EBC can be estimated using patients' pre-treatment characteristics.

Improved keratinocyte carcinoma outcomes with annual dermatology assessment after solid organ transplantation: Population-based cohort study.

Solid organ transplant recipients have a high risk of keratinocyte carcinoma (non-melanoma skin cancer). Consensus-based transplant guidelines recommend annual dermatological examination but the impact on skin cancer-related outcomes is unclear. We conducted a population-based, retrospective, inception cohort study using administrative health databases in Ontario, Canada to evaluate the association between adherence to annual dermatology assessments (time-varying exposure) and keratinocyte carcinoma-related morbidity and mortality after transplantation. The primary outcome was the time to first advanced (highly morbid or fatal) keratinocyte carcinoma. Among 10 183 adults receiving their first transplant from 1994 to 2012 and followed for a median of 5.44 years, 4.9% developed an advanced keratinocyte carcinoma after transplant. Adherence to annual dermatology assessments for at least 75% of the observation time after transplant was associated with a 34% reduction in keratinocyte carcinoma-related morbidity or death compared with adherence levels below 75% (adjusted hazard ratio 0.66, 95% CI 0.48-0.92). Adherence levels were universally low (median proportion of time spent in adherence 0%, inter-quartile range 0-27%). Only 45% of transplant recipients had ever seen a dermatologist and 2.1% were fully adherent during the entire observation period. Strategies are needed to improve adherence rates in order to help decrease long-term morbidity after transplant.

The Association Between Insulin Initiation and Adverse Outcomes After Hospital Discharge in Older Adults: a Population-Based Cohort Study.

BACKGROUND: Starting insulin therapy in hospitalized patients may be associated with an increase in serious adverse events after discharge. OBJECTIVE: Determine whether post-discharge risks of death and rehospitalization are higher for older hospitalized patients prescribed new insulin therapy compared with oral hypoglycemic agents (OHAs). DESIGN: Retrospective population-based cohort study including hospital admissions in Ontario, Canada, between April 1, 2004, and Nov 30, 2013. PATIENTS: Persons aged 66 and over discharged after a hospitalization and dispensed a prescription for insulin and/or an OHA within 7 days of discharge. We included 104,525 individuals, subcategorized into four mutually exclusive exposure groups based on anti-hyperglycemic drug use in the 7 days post-discharge and the 365 days prior to the index admission. MAIN MEASURES: Prescriptions at discharge were categorized as new insulin (no insulin before admission), prevalent insulin (prescribed insulin before admission), new OHA(s) (no OHA or insulin before admission), and prevalent OHA (prescribed OHA only before admission) as the referent category. The primary and secondary outcomes were 30-day deaths and emergency department (ED) visits or readmissions respectively. KEY RESULTS: Of 104,525 patients, 9.2% were initiated on insulin, 4.1% died, and 26.2% had an ED visit or readmission within 30 days of discharge. Deaths occurred in 7.14% of new insulin users, 4.86% of prevalent insulin users, 3.25% of new OHA users, and 3.45% of prevalent OHA users. After adjustment for covariates, new insulin users had a significantly higher risk of death (adjusted hazard ratio (aHR) 1.59, 95% confidence interval (CI) 1.46 to 1.74) and ED visit/readmissions (aHR 1.17, 95% CI 1.12 to 1.22) than prevalent OHA users. CONCLUSIONS: Initiation of insulin therapy in older hospitalized patients is associated with a higher risk of death and ED visits/readmissions after discharge, highlighting a need for better transitional care of insulin-treated patients.

Health care utilization by people with HIV on release from provincial prison in Ontario, Canada in 2010: a retrospective cohort study.

Limited evidence suggests that at the time of release from prison, people with HIV face barriers to health care, which may contribute to worsening HIV clinical outcomes. We aimed to describe health care utilization for people with HIV released from provincial prison in Ontario in 2010, and to compare rates of use with prisoner and general population controls. We used Ontario's administrative health records and data from the Ontario Ministry of Community Safety and Correctional Services on all persons released from provincial prison in 2010. We matched each person with HIV released from provincial prison by age and sex with three controls in each of three groups: people with no HIV released from provincial prison, people with HIV in the general population, and people with no HIV in the general population. We compared rates of use of primary care, non-primary ambulatory care, emergency departments, and hospitalization in the year after the first release from provincial prison in 2010 and in the corresponding period for matched controls. We identified 330 persons with HIV released from provincial prison in 2010. Their median time to first HIV-ambulatory care visit after prison release was 177 days (SD 136-239). Compared to all control groups, people with HIV released from provincial prison had higher rates of primary care use, unscheduled emergency department visits and hospital admissions at 30, 90 and 365 days after release. People with HIV released from provincial prison have a long time to first contact with HIV ambulatory care, and higher rates of health care utilization across health care settings. Interventions are required to facilitate post-release linkage to care for this population.

Attachment to primary care and team-based primary care: Retrospective cohort study of people who experienced imprisonment in Ontario.

OBJECTIVE: To examine attachment to primary care and team-based primary care in the community for people who experienced imprisonment in Ontario, and to compare these attachment data with data for the general population. DESIGN: Population-based retrospective cohort study. SETTING: Ontario. PARTICIPANTS: All persons released from provincial prison in Ontario to the community in 2010 who were linked with provincial health administrative data, and an age- and sex-matched general population group. MAIN OUTCOME MEASURES: Primary care attachment and team-based primary care attachment in the 2 years before admission to provincial prison (baseline) and in the 2 years after release in 2010 (follow-up) for the prison release group, and for the corresponding periods for the general population group. RESULTS: People in the prison release group (n = 48 861) were less likely to be attached to primary care compared with the age- and sex-matched general population group (n = 195 444), at 58.9% versus 84.1% at baseline (P < .001) and 63.0% versus 84.4% during follow-up (P < .001), respectively. The difference in attachment to team-based primary care was small in magnitude but statistically significant, at 14.4% versus 16.1% at baseline (P < .001) and 19.9% versus 21.6% during follow-up (P < .001), respectively. CONCLUSION: People who experience imprisonment have lower primary care attachment compared with the general population. Efforts should be made to understand barriers and to facilitate access to high-quality primary care for this population, including through initiatives to link people while in prison with primary care in the community.

Care setting and 30-day hospital readmissions among older adults: a population-based cohort study.

BACKGROUND: Despite the fact that many older adults receive home or long-term care services, the effect of these care settings on hospital readmission is often overlooked. Efforts to reduce hospital readmissions, including capacity planning and targeting of interventions, require clear data on the frequency of and risk factors for readmission among different populations of older adults. METHODS: We identified all adults older than 65 years discharged from an unplanned medical hospital stay in Ontario between April 2008 and December 2015. We defined 2 preadmission care settings (community, long-term care) and 3 discharge care settings (community, home care, long-term care) and used multinomial regression to estimate associations with 30-day readmission (and death as a competing risk). RESULTS: We identified 701 527 individuals (mean age 78.4 yr), of whom 414 302 (59.1%) started in and returned to the community. Overall, 88 305 in dividuals (12.6%) were re admitted within 30 days, but this proportion varied by care setting combination. Relative to individuals returning to the community, those discharged to the community with home care (adjusted odds ratio [OR] 1.43, 95% confidence interval [CI] 1.39-1.46) and those returning to long-term care (adjusted OR 1.35, 95% CI 1.27-1.43) had a greater risk of readmission, whereas those newly admitted to long-term care had a lower risk of readmission (adjusted OR 0.68, 95% CI 0.63-0.72). INTERPRETATION: In Ontario, about 40% of older people were discharged from hospital to either home care or long-term care. These discharge settings, as well as whether an individual was admitted to hospital from long-term care, have important implications for understanding 30-day readmission rates. System planning and efforts to reduce readmission among older adults should take into account care settings at both admission and discharge.

Unique Characteristics of High-Cost Users of Medical Care With Comorbid Mental Illness or Addiction in a Population-Based Cohort.

OBJECTIVE: To understand whether high-cost users of medical care with and without comorbid mental illness or addiction differ in terms of their sociodemographic and health characteristics. Unique characteristics would warrant different considerations for interventions and service design aimed at reducing unnecessary health care utilization and associated costs. METHODS: From the top 10% of Ontarians ranked by total medical care costs during fiscal year 2011/2012 (N = 314,936), prior 2-year mental illness or addiction diagnoses were determined from administrative data. Sociodemographics, medical illness characteristics, medical costs, and utilization were compared between those high-cost users of medical care with and without comorbid mental illness or addiction. Odds of being a frequent user of inpatient (≥3 admissions) and emergency (≥5 visits) services were compared between groups, adjusting for age, sex, socioeconomic status and medical illness characteristics. RESULTS: High-cost users of medical care with comorbid mental illness or addiction were younger, had a lower socioeconomic status, had greater historical medical morbidity, and had higher total medical care costs (mean excess of $2,031/user) than those without. They were more likely to be frequent users of inpatient (12.8% vs 10.2%; adjusted OR, 1.14; 95% CI: 1.12-1.17) and emergency (8.4% vs 4.8%; adjusted OR, 1.55; 95% CI: 1.50-1.59) services. Effect sizes were larger in major mood, psychotic, and substance use disorder subgroups. CONCLUSIONS: High-cost medical care users with mental illness or addiction have unique characteristics with respect to sociodemographics and service utilization patterns to consider in interventions and policies for this patient group.

Acute Care Use for Ambulatory Care-Sensitive Conditions in High-Cost Users of Medical Care with Mental Illness and Addictions.

OBJECTIVE: The role of mental illness and addiction in acute care use for chronic medical conditions that are sensitive to ambulatory care management requires focussed attention. This study examines how mental illness or addiction affects risk for repeat hospitalization and/or emergency department use for ambulatory care-sensitive conditions (ACSCs) among high-cost users of medical care. METHOD: A retrospective, population-based cohort study using data from Ontario, Canada. Among the top 10% of medical care users ranked by cost, we determined rates of any and repeat care use (hospitalizations and emergency department [ED] visits) between April 1, 2011, and March 31, 2012, for 14 consensus established ACSCs and compared them between those with and without diagnosed mental illness or addiction during the 2 years prior. Risk ratios were adjusted (aRR) for age, sex, residence, and income quintile. RESULTS: Among 314,936 high-cost users, 35.9% had a mental illness or addiction. Compared to those without, individuals with mental illness or addiction were more likely to have an ED visit or hospitalization for any ACSC (22.8% vs. 19.6%; aRR, 1.21; 95% confidence interval [CI], 1.20-1.23). They were also more likely to have repeat ED visits or hospitalizations for the same ACSC (6.2% vs. 4.4% of those without; aRR, 1.48; 95% CI, 1.44-1.53). These associations were stronger in stratifications by mental illness diagnostic subgroup, particularly for those with a major mental illness. CONCLUSIONS: The presence of mental illness and addiction among high-cost users of medical services may represent an unmet need for quality ambulatory and primary care.