Cardiovascular Diseases (CVD) have become the leading cause of death in India and other developing countries. The aims of this study were to: (1) describe the geographical epidemiology of CVD in India, (2) provide a graphical display of CVD risk factors and mortality outcomes, and (3) describe the sources of bias. Five large, nationally-representative datasets from India were studied. Cardiovascular death rates were 308/100,000 among males and 198/100,000 among females in middle-age (30-69years). Wide variations between states were noted in the distribution of risk factors and mortality. The selected risk factors explained 49% and 43% of the variation among males and females respectively. Ecologic analysis revealed death rates at state-level were associated with rates of overweight and vegetarianism among males; no such association was found among females. This study has implications for identification of areas with high burden, formulation of hypotheses, and assessing needs for disease control at national/regional levels.

Aim: To describe the longitudinal active joint count (AJC) trajectories in juvenile idiopathic arthritis (JIA). Methods: A retrospective cohort study at two Canadian centres was performed. The longitudinal trajectories of AJC were described using latent growth curve modeling. The association of baseline characteristics stratified by trajectory group was examined by univariate methods. Results: Data were analyzed for 659 children diagnosed with JIA between 1990/03-2009/09. A maximum of 10 years of follow-up data were included in the analysis. Participants were classified into 5 statistically and clinically distinct AJC trajectories by latent GCM. Conclusions: Using a novel longitudinal statistical method we were able to classify patients with JIA based on their pattern of AJC over time. The trajectory classes need to be examined for their relationship to important genetic and biological predictors. Identification of patterns of disease course is important in working towards the development of a clinically relevant outcome-based classification system in JIA.

This study examined the potential impact on processes of care and patient outcomes upon exposure of supportive and concurrent care provided by primary care providers (PCPs) to their hospitalized patients. A secondary objective was to describe the PCPs who conduct these services, and the patients who receive them. There was a marked, observable trend that PCP visits to their hospitalized patients is on the decline (dropped 10% between 2003 and 2009). The patients who received in-hospital visits from their PCPs had more disease burden and were hospitalized longer than the control group. Patients who received and in-hospital visit from their PCP were more likely to receive home care services and PCP visits post-discharge [adjusted OR 1.20 (95% CI 1.12-1.28)]. They were also less likely to experience the composite outcome of death, hospital readmission, or emergency department visit [aOR 0.95 (95% CI 0.91-0.98)].

Background: Nosocomial pneumonia (NP) is a significant cause of morbidity and mortality in hospitalized patients. Objective: The objectives of this study were to describe the epidemiology of NP in adult patients hospitalized in Canadian acute care facilities and identify prognostic indicators for death. Methods: A retrospective cohort study was conducted in 114 patients with NP admitted to hospitals that participated in a 2002 Canadian point prevalence survey. Results: A high proportion of NP patients had a rapidly or ultimately fatal underlying illness. NP in non-intensive care unit (ICU) patients accounted for the larger proportion of these infections.There was no mortality difference between patients with and without ventilator-associated NP, or with and without ICU-acquired NP. Delayed initiation of appropriate antimicrobial therapy was associated with a poorer outcome. Discussion: Strategies that result in the timely administration of appropriate antimicrobial therapy should be investigated in an effort to reduce NP-associated mortality.

Aim: To describe the longitudinal active joint count (AJC) trajectories in juvenile idiopathic arthritis (JIA). Methods: A retrospective cohort study at two Canadian centres was performed. The longitudinal trajectories of AJC were described using latent growth curve modeling. The association of baseline characteristics stratified by trajectory group was examined by univariate methods. Results: Data were analyzed for 659 children diagnosed with JIA between 1990/03-2009/09. A maximum of 10 years of follow-up data were included in the analysis. Participants were classified into 5 statistically and clinically distinct AJC trajectories by latent GCM. Conclusions: Using a novel longitudinal statistical method we were able to classify patients with JIA based on their pattern of AJC over time. The trajectory classes need to be examined for their relationship to important genetic and biological predictors. Identification of patterns of disease course is important in working towards the development of a clinically relevant outcome-based classification system in JIA.

Background: Nosocomial pneumonia (NP) is a significant cause of morbidity and mortality in hospitalized patients. Objective: The objectives of this study were to describe the epidemiology of NP in adult patients hospitalized in Canadian acute care facilities and identify prognostic indicators for death. Methods: A retrospective cohort study was conducted in 114 patients with NP admitted to hospitals that participated in a 2002 Canadian point prevalence survey. Results: A high proportion of NP patients had a rapidly or ultimately fatal underlying illness. NP in non-intensive care unit (ICU) patients accounted for the larger proportion of these infections.There was no mortality difference between patients with and without ventilator-associated NP, or with and without ICU-acquired NP. Delayed initiation of appropriate antimicrobial therapy was associated with a poorer outcome. Discussion: Strategies that result in the timely administration of appropriate antimicrobial therapy should be investigated in an effort to reduce NP-associated mortality.

This study examined the potential impact on processes of care and patient outcomes upon exposure of supportive and concurrent care provided by primary care providers (PCPs) to their hospitalized patients. A secondary objective was to describe the PCPs who conduct these services, and the patients who receive them. There was a marked, observable trend that PCP visits to their hospitalized patients is on the decline (dropped 10% between 2003 and 2009). The patients who received in-hospital visits from their PCPs had more disease burden and were hospitalized longer than the control group. Patients who received and in-hospital visit from their PCP were more likely to receive home care services and PCP visits post-discharge [adjusted OR 1.20 (95% CI 1.12-1.28)]. They were also less likely to experience the composite outcome of death, hospital readmission, or emergency department visit [aOR 0.95 (95% CI 0.91-0.98)].

This thesis comprises a detailed analysis of sexual risk behavior among female sex workers participating in a prospective cohort study in Mombasa, Kenya between 1993 and 2007. To determine whether high-risk behavior has decreased over time, I examined trends in and associations with condom use and partner numbers at enrolment and over follow-up using multinomial logistic regression. While condom use increased among women enrolling into the cohort, women reduced partner numbers, rather than increasing condom use, over cohort visits. Workplace, charge for sex, duration of sex work, alcohol use, pregnancy and illness were all predictors of condom use. To evaluate the extent to which HIV risk estimates were affected by loss to follow-up, I investigated associations between sexual risk behavior, loss to follow-up, and HIV acquisition, using competing risks regression. Women reporting unprotected sex with multiple partners had the highest risk for HIV infection, and were also most likely to remain in the cohort. Finally, I used Andersen-Gill modeling to assess the impact of sexual risk behaviors on acquisition of sexually transmitted infections (STI) including gonorrhea, non-specific cervicitis, and trichomoniasis. While incident gonorrhea was closely associated with recent sexual risk behavior, incident trichomoniasis was not. Both conditions had high hazards for recurring in a 90-day window after a prior diagnosis. Non-specific cervicitis was demonstrated to be a chronic, relapsing condition associated with protected sex with multiple partners (possibly due to more frequent condom use) and with known biologic risk factors (i.e., pregnancy, hormonal contraceptive use, cervical ectopy, and genital ulcer disease). Overall, these analyses have led to a better understanding of how different sexual behavior patterns are associated with adverse outcomes, including HIV and STI acquisition, and identified specific factors associated with high-risk sexual behavior that may be amenable to intervention.

Violence and traumatic brain injury (TBI) are two major public health concerns. This thesis is comprised of three different research topics; the epidemiology of intentional TBI in Ontario, discharge against medical advice (DAMA) as an undesirable outcome of acute stage, and functional changes after receiving rehabilitation care. To study these areas, three different datasets from the Canadian Institute for Health Information (CIHI) were used. The first epidemiological study on intentional TBI identified 1,409 (8.0%) intentional TBIs and 16,211 (92.0%) unintentional TBIs. Of the intentional TBIs, 389 (27.6%) were self-inflicted TBI (Si-TBI) and 1,020 (72.4%) were other-inflicted TBI (Oi-TBI). The most common causes of Si-TBI were “jumping from high places” and “firearms”. Major causes of Oi-TBI were ‘fight and brawl” and “struck by objects”. Si-TBI was associated with younger age, female gender, and having a history of alcohol/drug abuse. Oi-TBI was also associated with younger age and having an alcohol/drug abuse history and also with male gender. The second study on discharge against medical advice found that 446 (2.84%) TBI patients left hospitals without medical advice. DAMA was significantly associated with intentional injuries in those with self-inflicted TBI and other-inflicted TBI. DAMA was also associated with younger age and a history of alcohol/drug abuse. Using univariate analyses, the third study found that people with intentional TBI had significantly lower FIM gains in the motor area and significantly lower relative function gains (as measured by Montebello Rehabilitation Factor Score) in the cognitive area. Multivariate analyses of the same data showed that intentional TBI was also associated with lower cognitive relative gains, while controlling for age, gender, alcohol/abuse history, and other demographic and clinical variables. Persons with intentional TBI were found to be less likely to be discharged home, controlling for other relevant confounders. In conclusion, a person who has been injured due to assault or suicidal attempt may need more individualized care as they may be at greater risk for adverse rehabilitation outcomes. These findings regarding people with intentional TBI provide a basis for enhancing efforts on prevention of violence-related TBI and DAMA, and also for improving rehabilitation programs and discharge plans for this vulnerable population.

Cardiovascular Diseases (CVD) have become the leading cause of death in India and other developing countries. The aims of this study were to: (1) describe the geographical epidemiology of CVD in India, (2) provide a graphical display of CVD risk factors and mortality outcomes, and (3) describe the sources of bias. Five large, nationally-representative datasets from India were studied. Cardiovascular death rates were 308/100,000 among males and 198/100,000 among females in middle-age (30-69years). Wide variations between states were noted in the distribution of risk factors and mortality. The selected risk factors explained 49% and 43% of the variation among males and females respectively. Ecologic analysis revealed death rates at state-level were associated with rates of overweight and vegetarianism among males; no such association was found among females. This study has implications for identification of areas with high burden, formulation of hypotheses, and assessing needs for disease control at national/regional levels.