The impact of pertussis vaccine programme changes on pertussis disease burden in Manitoba, 1992-2017-an age-period-cohort analysis.

BACKGROUND: Changes to pertussis vaccination programmes can have impacts on disease burden that should be estimated independently from factors such as age- and period-related trends. We used age-period-cohort (APC) models to explore pertussis incidence in Manitoba over a 25-year period (1992-2017). METHODS: We identified all laboratory-confirmed cases of pertussis from Manitoba's Communicable Diseases Database and calculated age-standardized incidence rates. We used APC models to investigate trends in pertussis incidence. RESULTS: During the study period, 2479 cases were reported. Age-standardized rates were highest during a large outbreak in 1994 (55 cases/100 000 person-years), with much lower peaks in 1998, 2012 and 2016. We saw strong age and cohort effects in the APC models, with a steady decrease in incidence with increasing age and increased risk in the cohort born between 1980 and 1995. CONCLUSIONS: The highest risk for pertussis was consistently in young children, regardless of birth cohort or time period. The 1981 programme change to an adsorbed whole-cell pertussis vaccine with low effectiveness resulted in reduced protection in the 1981-95 birth cohort and contributed to the largest outbreak of disease during the 25-year study period.

Pertussis vaccine effectiveness and duration of protection - A systematic review and meta-analysis.

A comprehensive review of observational pertussis vaccine effectiveness (VE) studies is needed to update gaps from previous reviews. We conducted a systematic review of VE and duration of protection studies for the whole-cell (wP) and acellular (aP) pertussis vaccines and conducted a formal meta-analysis using random effects models. Evidence continues to suggest that receipt of any pertussis vaccine confers protection in the short-term against disease although this protection wanes rapidly for aP vaccine. We detected significant heterogeneity in pooled estimates due, in part, to factors such as bias and confounding which may be mitigated by study design. Our review of possible sources of heterogeneity may help interpretation of other VE studies and aid design decisions in future pertussis VE research.

Comparing the Ecological Niches of Chlamydial and Gonococcal Infections in Winnipeg, Canada: 2007-2016.

BACKGROUND: Previous studies have shown substantial differences in geographic clustering of sexually transmitted infections (STI), such as chlamydia (CT) and gonorrhea (NG), conditional on epidemic phase. Chlamydia and NG have recently shown resurgent epidemiology in the northern hemisphere. This study describes the recent epidemiology of CT and NG in Winnipeg, Canada, combining traditional surveillance tools with place-based analyses, and comparing the ecological niches of CT and NG, in the context of their evolving epidemiology. METHODS: Data were collected as part of routine public health surveillance between 2007 and 2016. Secular trends for CT and NG, and CT/NG coinfection were examined. Gini coefficients and population attributable fractions explored the distribution, and concentration of infections over time and space. RESULTS: Rates of CT increased from 394.9/100,000 population to 476.2/100,000 population from 2007 to 2016. Gonorrhea rates increased from 78.0/100,000 population to 143.5/100,000 population during the same period. Each pathogen had its own ecological niche: CT was widespread geographically and socio-demographically, while NG was clustered in Winnipeg's inner-core. CT/NG co-infections had the narrowest space and age distribution. NG was shown to be undergoing a growth phase, with clear signs of geographic dispersion. The expansion of NG resembled the geographic distribution of CT. CONCLUSIONS: We demonstrated that NG was experiencing a growth phase, confirming theoretical predictions of geographic dispersion during a growth phase. During this phase, NG occupied similar geographic spaces as CT. Knowledge of different ecological niches could lead to better targeting of resources for subpopulations vulnerable to STIs.

Lower prevalence of multiple sclerosis in First Nations Canadians.

BACKGROUND: We compared the incidence and prevalence of multiple sclerosis (MS) between First Nations (FN) and non-FN populations in Manitoba. METHODS: We applied previously validated algorithms to population-based administrative (health claims) data from Manitoba, Canada, to identify all persons with MS from 1984 to 2011. We identified FN individuals using the Municipality of Registration field held at Manitoba Health. We compared the incidence and prevalence of MS between the FN and non-FN populations using negative binomial models. RESULTS: From 1984 to 2011, 5,738 persons had MS, of whom 64 (1.1%) were of FN ethnicity. The average annual incidence rate per 100,000 population was 8.15 (95% confidence interval [CI] 5.98-11.1) in the FN population and 15.7 (95% CI 15.1-16.3) in the non-FN population (incidence rate ratio 0.52; 95% CI 0.38-0.71). In 1984, the crude prevalence of MS per 100,000 population was 35.8 (95% CI 14.9-86.1) in the FN population and 113.3 (95% CI 106.3-120.8) in the non-FN population. Between 1984 and 2011, the age-standardized prevalence of MS increased by 351% to 188.5 (95% CI 146.6-230.4) in the FN population. In contrast, the prevalence of MS per 100,000 general population increased by 225%-418.4% (95% CI 405.8-431.0). CONCLUSIONS: The incidence and prevalence of MS are twofold lower in the FN population than the non-FN population. Nonetheless, the prevalence of MS in FN Manitobans is higher than in other indigenous populations outside Canada. Given reports of more rapid disability progression among FN Canadians with MS, and the rising prevalence of MS in this population, attention should be directed to the needs of this population.

Epidemiology of incident chlamydia and gonorrhoea infections and population attributable fractions associated with living in the inner-core of Winnipeg, Canada.

Population attributable fractions help to convey public health significance of differential disease risk for chlamydia and gonorrhoea. Geographical residence serves as a useful proxy for complex processes creating ill health. Using population-based data, Poisson regression models were used to examine factors associated with chlamydia and gonorrhoea incidence. Population attributable fractions due to residency in the Winnipeg Health Region's inner-core were determined for chlamydia/gonorrhoea infections among 15-59-year olds (2005-2013), stratified by age group. For both chlamydia and gonorrhoea, it was found that the 15-24-year old age group had the highest incidence rates. There was also a stronger association between residency in the inner-core and incidence for gonorrhoea, compared to chlamydia. Overall, 24% (95% CI: 12-34%) of chlamydia infections were attributable to residency in the inner-core, compared to 46% (95% CI: 35-54%) for gonorrhoea ( p < .05). Within chlamydia/gonorrhoea, no statistically significant differences in population attributable fraction were observed by age group. The conclusion was that a concentration of efforts towards inner-core residents with gonorrhoea infections may result in a relatively larger decrease in incidence.

Infectious syphilis in women: what's old is new again?

The aim of this study was to examine trends in infectious syphilis epidemiology among women in Winnipeg, Canada. A descriptive study of syphilis among Winnipeg residents between 2003 and 30 June 2015 was undertaken. Adjusted rate ratios (ARR) and 95% confidence intervals (95%CI) from Poisson regression analyses are reported. Characteristics of men and women were compared using logistic regression, with adjusted odds ratios (AOR) reported. Between 2014 and 2015, the rate of syphilis was 1.7/100,000, representing a five-fold increase since 2006-2013. All cases have been heterosexual, 90% 20-39 years of age, and 59% living in Winnipeg's inner core. Approximately 24% were pregnant at diagnosis; no cases of congenital syphilis have been reported. Compared to men, women were more likely to report alcohol use (AOR: 3.8, 95% CI: 1.2-11.9) and co-infection with chlamydia (AOR: 5.0, 95% CI: 1.1-22.9). In conclusion, the rates of infectious syphilis are increasing among women. Prenatal screening and education for inner-core women and the health care providers serving them should be prioritized.

Physical comorbidities increase the risk of psychiatric comorbidity in multiple sclerosis.

BACKGROUND: Risk factors for psychiatric comorbidity in multiple sclerosis (MS) are poorly understood. OBJECTIVE: We evaluated the association between physical comorbidity and incident depression, anxiety disorder, and bipolar disorder in a MS population relative to a matched general population cohort. METHODS: Using population-based administrative data from Alberta, Canada we identified 9624 persons with MS, and 41,194 matches. Using validated case definitions, we estimated the incidence of depression, anxiety disorder, and bipolar disorder, and their association with physical comorbidities using Cox regression, adjusting for age, sex, socioeconomic status, and index year. RESULTS: In both populations, men had a lower risk of depression and anxiety disorders than women, as did individuals who were ≥45 years versus <45 years at the index date. The risk of bipolar disorder declined with increasing age. The risks of incident depression (HR 1.92; 1.82-2.04), anxiety disorders (HR 1.52; 1.42-1.63), and bipolar disorder (HR 2.67; 2.29-3.11) were higher in the MS population than the matched population. These associations persisted essentially unchanged after adjustment for covariates including physical comorbidities. Multiple physical comorbidities were associated with psychiatric disorders in both populations. CONCLUSION: Persons with MS are at increased risk of psychiatric comorbidity generally, and some physical comorbidities are associated with additional risk.

Chronic lung disease and multiple sclerosis: Incidence, prevalence, and temporal trends.

OBJECTIVES: We aimed to estimate the incidence and prevalence of chronic lung disease (CLD), including asthma and chronic obstructive pulmonary disease, in the MS population versus a matched cohort from the general population. METHODS: We used population-based administrative data from four Canadian provinces to identify 44,452 persons with MS and 220,849 age-, sex- and geographically-matched controls aged 20 years and older. We employed a validated case definition to estimate the incidence and prevalence of CLD over the period 1995-2005, and used Poisson regression to assess temporal trends. RESULTS: In 2005, the crude incidence of CLD per 100,000 persons was 806 (95%CI: 701-911) in the MS population, and 757 in the matched population (95%CI: 712-803). In 2005, the crude prevalence of CLD was 13.5% (95%CI: 13.1-14.0%) in the MS population, and 12.4% (95%CI: 12.3-12.6%) in the matched population. Among persons aged 20-44 years, the average annual incidence of CLD was higher in the MS population than in the matched population (RR 1.15; 95%CI: 1.02-1.30), but did not differ between populations for those aged ≥45 years. The incidence of CLD was stable, but the prevalence of CLD increased 60% over the study period. CONCLUSION: CLD is relatively common in the MS population. The incidence of CLD has been stable over time, but the prevalence of CLD has increased. Among persons aged 20-44 years, CLD is more common in the MS population than in a matched population. Given the prevalence of CLD in the MS population, further attention to the effects of CLD on outcomes in MS and approaches to mitigating those effects are warranted.

Did the H1N1 Vaccine Reduce the Risk of Admission with Influenza and Pneumonia during the Pandemic?

BACKGROUND: The extent to which A(H1N1)pdm09 influenza vaccines prevented hospital admissions with pneumonia and influenza (P&I) during the 2009 pandemic remains poorly understood. We evaluated the effectiveness of the A(H1N1)pdm09 and seasonal influenza vaccines (TIV) used during the 2009 mass vaccination campaign in Manitoba (Canada) in preventing P&I hospitalization. METHODS: A population-based record-linkage nested case-control study. Cases (N = 1,812) were persons hospitalized with influenza (ICD-10:J09-J11) or pneumonia (ICD-10:J12-J18) during the study period. Age-, gender- and area of residence-matched controls (N = 7,915) were randomly sampled from Manitoba's Population Registry. Information on receipt of A(H1N1)pdm09 vaccine and TIV was obtained from the Manitoba Immunization Monitoring System, a province-wide vaccine registry. RESULTS: Overall, the adjuvanted A(H1N1)pdm09 vaccine was 27% (95%CI 13-39%) effective against P&I hospitalization ≥ 14 days following administration. Effectiveness seemed lower among older (≥ 65 years) adults (10%; -16-30%), particularly when compared to under-5 children (58%; 30-75%). The number-needed-to-vaccinate to prevent 1 P&I admission was lowest among <4 year-olds (928) and ≥65 years (1,721). VE against hospitalization with laboratory-confirmed A(H1N1)pdm09 was 70% (39-85%) overall and (91%; 62-98%) ≥ 14 days following vaccination. DISCUSSION: Our data suggest that the adjuvanted A(H1N1)pdm09 vaccine was effective in preventing about 55-60% of P&I hospitalizations among children and younger adults who were at much higher risk of infection. Unfortunately, the vaccine was less effective among 65 or older adults. Despite that the vaccine still had a significant population-based impact especially among the very young (<5) and the older (≥ 65 years).

Between a rock and a hard place: Smoking trends in a Manitoba First Nation.

OBJECTIVES: The purpose of this study is to estimate and compare smoking prevalence over two time periods in a Manitoba First Nation community. METHODS: Data fromtwo independent Diabetes Screening Studies in Sandy Bay First Nation, collected in 2002/2003 (n = 482) and 2011/2012 (n = 596),were used. Crude prevalence of current and ever smoking as well as current smoke exposure was estimated. Change over time was tested using a χ² statistic. RESULTS: The crude prevalence of current smoking was 74.0% (95% confidence interval [CI]: 70.1, 78.0) in 2002/2003 and 80.0% (95% CI: 76.8, 83.2) in 2011/2012. The crude prevalence of ever smoking was 83.0% in 2002/2003 and 91.4% in 2011/2012. The prevalence of both current smoking status and ever smoking were significantly higher in 2011/2012 compared to 2002/2003 (p = 0.020 and p < 0.001 respectively). Among participants who were not current smokers, 58.5% (95% CI: 49.6, 67.4) and 76.5% (95% CI: 68.9, 84.1) reported at least one person who smoked in the home in 2002/2003 and 2011/2012 respectively (p = 0.003). In 2011/2012, 96.5% (95% CI: 94.8, 98.2) of those who reported having any children under the age of 18 living in the home were either a current smoker and/or reported that someone else smoked in the home. CONCLUSION: Public health and policy initiatives are needed to address the increase in smoking prevalence in the study community.

High incidence and increasing prevalence of multiple sclerosis in British Columbia, Canada: findings from over two decades (1991-2010).

Province-wide population-based administrative health data from British Columbia (BC), Canada (population: approximately 4.5 million) were used to estimate the incidence and prevalence of multiple sclerosis (MS) and examine potential trends over time. All BC residents meeting validated health administrative case definitions for MS were identified using hospital, physician, death, and health registration files. Estimates of annual prevalence (1991-2008), and incidence (1996-2008; allowing a 5-year disease-free run-in period) were age and sex standardized to the 2001 Canadian population. Changes over time in incidence, prevalence and sex ratios were examined using Poisson and log-binomial regression. The incidence rate was stable [average: 7.8/100,000 (95 % CI 7.6, 8.1)], while the female: male ratio decreased (p = 0.045) but remained at or above 2 for all years (average 2.8:1). From 1991-2008, MS prevalence increased by 4.7 % on average per year (p < 0.001) from 78.8/100,000 (95 % CI 75.7, 82.0) to 179.9/100,000 (95 % CI 176.0, 183.8), the sex prevalence ratio increased from 2.27 to 2.78 (p < 0.001) and the peak prevalence age range increased from 45-49 to 55-59 years. MS incidence and prevalence in BC are among the highest in the world. Neither the incidence nor the incidence sex ratio increased over time. However, the prevalence and prevalence sex ratio increased significantly during the 18-year period, which may be explained by the increased peak prevalence age of MS, longer survival with MS and the greater life expectancy of women compared to men.

Effect of comorbidity on mortality in multiple sclerosis.

OBJECTIVE: We aimed to compare survival in the multiple sclerosis (MS) population with a matched cohort from the general population, and to evaluate the association of comorbidity with survival in both populations. METHODS: Using population-based administrative data, we identified 5,797 persons with MS and 28,807 controls matched on sex, year of birth, and region. We estimated annual mortality rates. Using Cox proportional hazards regression, we evaluated the association between comorbidity status and mortality, stratifying by birth cohort, and adjusting for sex, socioeconomic status, and region. We compared causes of death between populations. RESULTS: Median survival from birth in the MS population was 75.9 years vs 83.4 years in the matched population. MS was associated with a 2-fold increased risk of death (adjusted hazard ratio 2.40; 95% confidence interval: 2.24-2.58). Several comorbidities were associated with increased hazard of death in both populations, including diabetes, ischemic heart disease, depression, anxiety, and chronic lung disease. The magnitude of the associations of mortality with chronic lung disease, diabetes, hypertension, and ischemic heart disease was lower in the MS population than the matched population. The most common causes of death in the MS population were diseases of the nervous system and diseases of the circulatory system. Mortality rates due to infectious diseases and diseases of the respiratory system were higher in the MS population. CONCLUSION: In the MS population, survival remained shorter than expected. Within the MS population, comorbidity was associated with increased mortality risk. However, comorbidity did not preferentially increase mortality risk in the MS population as compared with controls.

Barriers and facilitators related to use of prenatal care by inner-city women: perceptions of health care providers.

BACKGROUND: Socioeconomic disparities in the use of prenatal care (PNC) exist even where care is universally available and publicly funded. Few studies have sought the perspectives of health care providers to understand and address this problem. The purpose of this study was to elicit the experiential knowledge of PNC providers in inner-city Winnipeg, Canada regarding their perceptions of the barriers and facilitators to PNC for the clients they serve and their suggestions on how PNC services might be improved to reduce disparities in utilization. METHODS: A descriptive exploratory qualitative design was used. Semi-structured interviews were conducted with 24 health care providers serving women in inner-city neighborhoods with high rates of inadequate PNC. Content analysis was used to code the interviews based on broad categories (barriers, facilitators, suggestions). Emerging themes and subthemes were then developed and revised through the use of comparative analysis. RESULTS: Many of the barriers identified related to personal challenges faced by inner-city women (e.g., child care, transportation, addictions, lack of support). Other barriers related to aspects of service provision: caregiver qualities (lack of time, negative behaviors), health system barriers (shortage of providers), and program/service characteristics (distance, long waits, short visits). Suggestions to improve care mirrored the facilitators identified and included ideas to make PNC more accessible and convenient, and more responsive to the complex needs of this population. CONCLUSIONS: The broad scope of our findings reflects a socio-ecological approach to understanding the many determinants that influence whether or not inner-city women use PNC services. A shift to community-based PNC supported by a multidisciplinary team and expanded midwifery services has potential to address many of the barriers identified in our study.

Perceptions of barriers, facilitators and motivators related to use of prenatal care: A qualitative descriptive study of inner-city women in Winnipeg, Canada.

OBJECTIVE: The objective of this qualitative descriptive study was to explore the perceptions of women living in inner-city Winnipeg, Canada, about barriers, facilitators, and motivators related to their use of prenatal care. METHODS: Individual, semi-structured interviews were conducted in person with 26 pregnant or postpartum women living in inner-city neighborhoods with high rates of inadequate prenatal care. Interviews averaged 67 min in length. Recruitment of participants continued until data saturation was achieved. Inductive content analysis was used to identify themes and subthemes under four broad topics of interest (barriers, facilitators, motivators, and suggestions). Sword's socio-ecological model of health services use provided the theoretical framework for the research. This model conceptualizes service use as a product of two interacting systems: the personal and situational attributes of potential users and the characteristics of health services. RESULTS: Half of the women in our sample were single and half self-identified as Aboriginal. Participants discussed several personal and system-related barriers affecting use of prenatal care, such as problems with transportation and child care, lack of prenatal care providers, and inaccessible services. Facilitating factors included transportation assistance, convenient location of services, positive care provider qualities, and tangible rewards. Women were motivated to attend prenatal care to gain knowledge and skills and to have a healthy baby. CONCLUSION: Consistent with the theoretical framework, women's utilization of prenatal care was a product of two interacting systems, with several barriers related to personal and situational factors affecting women's lives, while other barriers were related to problems with service delivery and the broader healthcare system. Overcoming barriers to prenatal care and capitalizing on factors that motivate women to seek prenatal care despite difficult living circumstances may help improve use of prenatal care by inner-city women.

Comorbidity increases the risk of hospitalizations in multiple sclerosis.

OBJECTIVE: We aimed to evaluate the association between comorbidity and rates of hospitalization in the multiple sclerosis (MS) population as compared to a matched cohort from the general population. METHODS: Using population-based administrative data from the Canadian province of Manitoba, we identified 4,875 persons with MS and a matched general population cohort of 24,533 persons. We identified all acute care hospitalizations in the period 2007-2011. Using general linear models, we evaluated the association between comorbidity status and hospitalization rates (all-cause, non-MS-related, MS-related) in the 2 populations, adjusting for age, sex, and socioeconomic status. RESULTS: Comorbidity was common in both cohorts. Over the 5-year study period, the MS population had a 1.5-fold higher hospitalization rate (adjusted rate ratio [aRR] 1.56; 95% confidence interval [CI] 1.44-1.68) than the matched population. Any comorbidity was associated with a 2-fold increased risk of non-MS-related hospitalization rates (aRR 2.21; 95% CI 1.73-2.82) in the MS population, but a nearly 4-fold increase in hospitalization rates in the matched population (aRR 3.85; 95% CI 3.40-4.35). Comorbidity was not associated with rates of hospitalization for MS-related reasons, regardless of how comorbidity status was defined. CONCLUSIONS: In the MS population, comorbidity is associated with an increased risk of all-cause hospitalizations, suggesting that the prevention and management of comorbidity may reduce hospitalizations.

Dramatically changing rates and reasons for hospitalization in multiple sclerosis.

OBJECTIVE: We aimed to describe hospitalizations in the multiple sclerosis (MS) population, and to evaluate temporal trends in hospitalizations in the MS population compared to the general population. METHODS: Using population-based administrative data, we identified 5,797 persons with MS and a matched general population cohort of 28,769 persons. Using general linear models, we evaluated temporal trends in hospitalization rates and length of stay in the 2 populations over the period 1984-2011. RESULTS: In 1984 the hospitalization rate was 35 per 100 person-years in the MS population and 10.5 in the matched population (relative risk [RR] 3.33; 95% confidence interval: 1.67-6.64). Over the study period hospitalizations declined 75% in the MS population but only 41% in the matched population. The proportion of hospitalizations due to MS declined substantially from 43.4% in 1984 to 7.8% in 2011. The 3 most common non-MS-related reasons for admission in the MS population were diseases of the digestive, genitourinary, and circulatory systems. Admissions for bacterial pneumonia, influenza, urinary tract infections, and pressure ulcers occurred more often in the MS population than in the general population, while admissions for circulatory system disease and neoplasms occurred less often. Older age, male sex, and lower socioeconomic status were associated with increased hospitalization rates for non-MS-related reasons. CONCLUSIONS: Although hospitalization rates have declined dramatically in the MS population over the last quarter century, they remain higher than in the general population. Admissions for MS-related reasons now constitute only a small proportion of the reasons for hospitalization.

Barriers, motivators and facilitators related to prenatal care utilization among inner-city women in Winnipeg, Canada: a case-control study.

BACKGROUND: The reasons why women do not obtain prenatal care even when it is available and accessible are complex. Despite Canada's universally funded health care system, use of prenatal care varies widely across neighborhoods in Winnipeg, Manitoba, with the highest rates of inadequate prenatal care found in eight inner-city neighborhoods. The purpose of this study was to identify barriers, motivators and facilitators related to use of prenatal care among women living in these inner-city neighborhoods. METHODS: We conducted a case-control study with 202 cases (inadequate prenatal care) and 406 controls (adequate prenatal care), frequency matched 1:2 by neighborhood. Women were recruited during their postpartum hospital stay, and were interviewed using a structured questionnaire. Stratified analyses of barriers and motivators associated with inadequate prenatal care were conducted, and the Mantel-Haenszel common odds ratio (OR) was reported when the results were homogeneous across neighborhoods. Chi square analysis was used to test for differences in proportions of cases and controls reporting facilitators that would have helped them get more prenatal care. RESULTS: Of the 39 barriers assessed, 35 significantly increased the odds of inadequate prenatal care for inner-city women. Psychosocial issues that increased the likelihood of inadequate prenatal care included being under stress, having family problems, feeling depressed, "not thinking straight", and being worried that the baby would be apprehended by the child welfare agency. Structural barriers included not knowing where to get prenatal care, having a long wait to get an appointment, and having problems with child care or transportation. Attitudinal barriers included not planning or knowing about the pregnancy, thinking of having an abortion, and believing they did not need prenatal care. Of the 10 motivators assessed, four had a protective effect, such as the desire to learn how to protect one's health. Receiving incentives and getting help with transportation and child care would have facilitated women's attendance at prenatal care visits. CONCLUSIONS: Several psychosocial, attitudinal, economic and structural barriers increased the likelihood of inadequate prenatal care for women living in socioeconomically disadvantaged neighborhoods. Removing barriers to prenatal care and capitalizing on factors that motivate and facilitate women to seek prenatal care despite the challenges of their personal circumstances may help improve use of prenatal care by inner-city women.