Progressive multifocal leukoencephalopathy and Creutzfeldt-Jakob disease: population-wide incidences, comorbidities, costs of care, and outcomes.

Neurological disorders associated with chronic infections are often progressive as well as challenging to diagnose and manage. Among 4.4 million persons from 2004 to 2019 receiving universal health, progressive multifocal leukoencephalopathy (PML, n = 58) and Creutzfeldt-Jakob disease (CJD, n = 93) cases were identified, revealing stable yearly incidence rates with divergent comorbidities: HIV/AIDS affected 37.8% of PML cases while cerebrovascular disease affected 26.9% of CJD cases. Most CJD cases died within 1 year (73%) although PML cases lived beyond 5 years (34.1%) despite higher initial costs of care. PML and CJD represent important neurological disorders with evolving risk variables and impact on health care.

A cohort study of regional migration and the risks of attempted suicide and violent assault injury.

OBJECTIVES: We study the association between changing residence and risks of attempted suicide and violent assault injury in Alberta, Canada. Our primary objective is to understand whether a change in residence between urban, rural and semiurban areas is associated with increased risk of intentional injury. METHODS: Study subjects are a cohort of residents linked to data on emergency department and inpatient hospital admissions between 1999 and 2010. We used generalised estimating equations to model the effects of changing residence on risk of intentional injury while controlling for the influence of age, sex, socio-economic status, Aboriginal status and history of intentional injury. RESULTS: Changing residence is associated with an increase in the risk of both attempted suicide and violent assault injury. In the case of attempted suicide, this effect is strongest for persons between 20 and 35 years of age. For violent assault injuries, persons from rural regions that have recently moved to urban regions have higher risk of injuries, and women of rural origin are at higher risk of violent assault injury than women of urban origin. CONCLUSIONS: Our findings reveal an association between risk of intentional injuries and change of residence adjusting for geographical differences in injury risk. These findings suggest that intentional injury risk is associated with change in community at intraregional scales and that these populations may benefit from support that helps integrate them into their new communities.

The role of systematic reviews and meta-analyses of incidence and prevalence studies in neuroepidemiology.

BACKGROUND: Systematic reviews and meta-analyses on the incidence and prevalence of neurological conditions are important methods of quantifying the burden and risk of disease. METHODS: The rigorous methodology required in order to minimize publication bias, account for study heterogeneity, and variation in study quality are described. When appropriate, a meta-analysis is a powerful statistical tool that can help synthesize a vast literature quantitatively, taking into account study heterogeneity. As the epidemiology of neurological conditions continue to be widely studied internationally, systematic reviews and meta-analyses have become essential. RESULTS: If not conducted carefully, systematic reviews and meta-analyses in neuroepidemiology may lead to erroneous conclusions. It is important to consider various methodological, clinical and statistical factors at all stages of the review and analysis process. Detailed documentation should be kept to assist in the reporting process. CONCLUSIONS: Published reporting standards should be consulted when conducting systematic reviews and meta-analyses of the incidence and prevalence of neurological conditions, though reporting standards specific to neuroepidemiology are urgently needed.

Prevalence of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in food samples associated with foodborne illness in Alberta, Canada from 2007 to 2010.

Consumption of foods containing Staphylococcus aureus can cause severe gastro-intestinal illness. Given the fact that over the past decade, Canada has seen increasing rates of methicillin-resistant S. aureus (MRSA) carriage and infection, the objective of this study was to investigate the impact of methicillin-susceptible S. aureus (MSSA) and MRSA on foodborne illness in Alberta, Canada. Between January 2007 and December 2010, there were 693 food samples associated with foodborne investigations submitted to the Alberta Provincial Laboratory for Public Health (ProvLab). These foods were screened for: Bacillus cereus, Clostridium perfringens, S. aureus, Aeromonas spp., Campylobacter spp., Escherichia coli O157:H7, Salmonella, Shigella spp., and Yersinia spp. S. aureus was identified in 10.5% (73/693) of samples, and of these, 59% (43/73) were co-contaminated with at least one other organism on the screening panel. The S. aureus positive samples included 29 meat, 20 prepared foods containing meat, 11 prepared foods not containing meat, 10 dairy, and three produce. Methicillin-resistance was not detected in any isolates tested. These findings indicate that the presence of S. aureus in food associated with foodborne investigations is a cause for concern, and although MRSA was not found, the potential for outbreaks exists, and ongoing surveillance should be sustained.

Long-term mortality associated with community-onset bloodstream infection.

PURPOSE: Although bloodstream infection is widely recognized as an important cause of acute morbidity and mortality, long-term mortality outcomes are less well defined. The objective of this study was to define the early (≤28 days) and late (>28 days) mortality and assess determinants of late death following community-onset bloodstream infection. METHODS: All adult residents of the Calgary Zone who had community-onset bloodstream infections during the period 1 January 2003 and 31 December 2007 were included. The mortality outcome was assessed through to 31 December 2008. RESULTS: A total of 4,553 cases were identified, of which 2,105 (46%) were healthcare-associated and 2,448 (54%) were community-acquired. The 28-day, 90-day, and 365-day all-cause case-fatality rates were 561/4,553 (12%), 780/4,553 (17%), and 1,131 (25%), respectively. Within the first 28 days, the median time to death was 4 (interquartile range [IQR] 1-12) days, with 158 (28%) and 212 (38%) of early (≤28-day) deaths occurring by days 1 and 2, respectively. Among survivors to 28 days (n = 3,992), 570 (14%) suffered late 1-year mortality (i.e., death occurred between 29 and 365 days postinception). The most common causes of death in this cohort as listed by the vital statistics data were malignancy in 220 (39%), cardiovascular in 135 (24%), and infection-related in 37 (7%). Older age, higher Charlson score, prolonged initial admission duration, and healthcare-associated and polymicrobial infections were independently associated with late 1-year mortality. CONCLUSIONS: Community-onset bloodstream infection is associated with major early and late mortality.

Changing epidemiology of methicillin-resistant Staphylococcus aureus in Alberta, Canada: population-based surveillance, 2005-2008.

SUMMARYIncreasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) has been reported in Canada. We report the results of a prospective surveillance of MRSA infections in Alberta over a consecutive 3-year period. A total of 8910 unique clinical MRSA isolates was analysed from July 2005 to June 2008. The incidence of MRSA infection increased over the study period and was highest in males, age group ⩾85 years, and the Calgary Area. CMRSA10 (USA300) and CMRSA2 (USA100/800) were the most common PFGE strain types, representing 53·0% and 27·9% of all isolates, respectively. Significant differences were noted between MRSA strains in the source of infection and antimicrobial susceptibility. The incidence of MRSA infection in Alberta has nearly doubled in the last 3 years; this is attributed to the emergence of CMRSA10 as the predominant strain.

Increasing incidence and prevalence with limited survival gains among rural Albertans with diabetes: a retrospective cohort study, 1995-2006.

OBJECTIVE: To compare recent trends of diabetes prevalence, incidence and mortality between men and women living in urban and rural Alberta, Canada. METHODS: We tracked population trends in diabetes in adults based on diagnostic codes from provincial administrative health records from 1995 to 2006. Location of residence was defined by registered postal codes. Sex-stratified logistic regression with interactions was used to compare increases in rates over the past decade by location of residence, adjusting for age. RESULTS: Men in rural residences had the greatest increases in prevalence, at 61%, from 3.6 per 100 in 1995 to 5.8 per 100 in 2006, compared with a 55% increase in urban men, from 3.9 per 100 in 1995 to 6.0 per 100 in 2006 (P < 0.001). Diabetes incidence in rural men increased 61% while urban men had a similar increase of 59% (P = 0.177). Incidence was lower in women in both urban and rural locations, at 5.6 and 5.3 per 1000 in 2006. Overall, mortality rates decreased by 34% for urban men and 8% for rural men with diabetes (P = 0.006). Women with diabetes in rural areas had no decline in overall mortality, compared with a 28% reduction in urban women (P < 0.001). CONCLUSIONS: Diabetes prevalence remains highest in men, with the greatest increases seen in men living in rural residences. While mortality rates have declined substantially over the past decade for those people with diabetes living in urban settings, declines in mortality in rural areas have been much more modest (for men) or non-existent (for women).

Using administrative data to understand the geography of case ascertainment.

We examined the geographic variability of information generated from different case definitions of childhood asthma derived from administrative health data used in Alberta, Canada. Our objective was to determine if analyses based on different case ascertainment algorithms identify geographic clusters in the same region of the study area. Our study group was based on a closed cohort of asthmatic children born in 1988. We used a spatial scan statistic to identify variations in the approximate location of geographic clusters of asthma based on different case definitions. Our results indicate that the geographic patterns are not greatly affected by the case ascertainment algorithm or the source of data. For example, asthmatics identified from medical claims data showed similar clustering to asthmatics defined through hospitalization and emergency department data. However, estimates of prevalence and incidence require careful consideration and validation against other data sources.

Relationship between enteric pathogens and acute gastroenteritis disease severity: a prospective cohort study.

OBJECTIVES: To evaluate the relationship between individual bacterial and viral pathogens and disease severity. METHODS: Children <18 years with three or more episodes of vomiting and/or diarrhoea were enrolled in two Canadian paediatric emergency departments between December 2014 and August 2016. Specimens were analysed employing molecular panels, and outcome data were collected 14 days after enrolment. The primary outcome was severe disease over the entire illness (symptom onset until 14-day follow-up), quantified employing the Modified Vesikari Scale (MVS) score. The score was additionally analysed in two other time periods: index (symptom onset until enrolment) and follow-up (enrolment until 14-day follow-up). RESULTS: Median participant age was 20.7 (IQR: 11.3, 44.2) months; 47.4% (518/1093) and 73.4% (802/1093) of participants had index and total MVS scores ≥11, respectively. The most commonly identified pathogens were rotavirus (289/1093; 26.4%) and norovirus (258/1093; 23.6%). In multivariable analysis, severe disease over the entire illness was associated with rotavirus (OR = 9.60; 95%CI: 5.69, 16.19), Salmonella (OR = 6.61; 95%CI: 1.50, 29.17), adenovirus (OR = 2.53; 95%CI: 1.62, 3.97), and norovirus (OR = 1.43; 95%CI: 1.01, 2.01). Pathogens associated with severe disease at the index visit were: rotavirus only (OR = 6.13; 95%CI: 4.29, 8.75), Salmonella (OR = 4.59; 95%CI: 1.71, 12.29), adenovirus only (OR = 2.06; 95%CI: 1.41, 3.00), rotavirus plus adenovirus (OR = 3.15; 95%CI: 1.35, 7.37), and norovirus (OR = 0.68; 95%CI: 0.49, 0.94). During the follow-up period, rotavirus (OR = 2.21; 95%CI: 1.50, 3.25) and adenovirus (OR = 2.10; 95%CI: 1.39, 3.18) were associated with severe disease. CONCLUSIONS: In children presenting for emergency department care with acute gastroenteritis, pathogens identified were predominantly viruses, and several of which were associated with severe disease. Salmonella was the sole bacterium independently associated with severe disease.

Incidence of Guillain-Barré syndrome in Alberta, Canada: an administrative data study.

BACKGROUND: To examine the epidemiology of Guillain-Barré syndrome (GBS) in Alberta between 1994 and 2004 with data derived from hospital administration procedures. METHODS: Data from 3,959,857 individuals (1,956,841 females and 2,003,016 males) aged 1-110 years and residing in Alberta, Canada, were included in the analysis. A Poisson regression analysis was performed to determine the predictors of GBS events. RESULTS: After age and sex standardisation to the 2001 Canadian census population, incidence rates ranged from 0.97 to 2.32 per 100,000 over the course of the 11-year period, with a mean incidence of 1.6 per 100,000. Significant effects of gender, age group and year were found. Males were found to be 1.5 times more likely to acquire GBS than females. Relative to those in their first decade, the risk of acquiring GBS increased with advancing age, whereby the incidence in males peaked in the 7th decade of life and in females in the 8th decade of life. The incidence fluctuated over the 11-year period, with a minimum in 1998 and a maximum in 2004. CONCLUSIONS: The incidence of GBS in Alberta between 1994 and 2004 fluctuated within a narrow range, was similar to that previously reported worldwide, demonstrated a male preponderance and increased in elderly patients.

Health disparities in chickenpox or shingles in Alberta?

OBJECTIVE: Exploring for evidence of socio-economic health disparities in chickenpox and shingles in Alberta, Canada. METHODS: Chickenpox and shingles cases were identified from administrative data from Alberta's universal health care insurance system for 1994-2002. Incident cases were those with the earliest dated utilization of a health service (chickenpox: ICD9-CM 052/ICD10-CA B01; shingles: ICD9-CM 053/ ICD10-CA B02). Crude and age-specific rates were estimated for each year by an indicator of socio-demographic status based upon the nature of the payer and eligibility for health care premium subsidy (SES-proxy) for the provincial health care insurance system. RESULTS: Among young children there is a gradient of disparity in chickenpox rates prior to the year in which publicly funded vaccination programs were implemented. After this point, disparities decline but less so for First Nations children than for others. There was no evidence of disparity by SES-proxy for shingles. CONCLUSION: Publicly funded vaccination programs may effectively contribute to reduction in disease disparities for vaccine-preventable diseases. Further study is required to ascertain why disparities continue for First Nations children.

Prevalence of mental disorders in children living in Alberta, Canada, as determined from physician billing data.

BACKGROUND: The prevalence of mental disorders is often assessed using survey techniques. Although providing good estimates of prevalence, these techniques are time-consuming and expensive. OBJECTIVE: To estimate the prevalence of mental disorders among children aged 0 to 17 years living in Alberta, Canada, using health care administrative data. DESIGN: This was a cross-sectional study. International Classification of Diseases, Ninth Revision, Clinical Modification chapter 5 diagnostic codes from physician billing data were used. Codes were grouped into 10 categories. Prevalence rates for each category were calculated, stratified by age, sex, and premium subsidy status (a proxy for socioeconomic status). The age pattern, times of greatest risk, and the effect of sex on type and prevalence of mental disorder were estimated. SETTING: All fee-for-service health care venues in Alberta between April 1, 1995, and March 31, 1996, providing services to children registered with the Alberta Health Care Insurance Commission on March 31, 1996. RESULTS: Prevalence of mental disorders varied by disorder category, age, sex, and premium subsidy status. For boys, maximum prevalence of 9.5% occurred at age 10 years; for girls, maximum prevalence of 12.0% occurred at age 17 years. Mental disorders were most common in young boys and adolescent girls and among children receiving welfare. Distinct patterns of disorder were evident and comorbidity was common. CONCLUSIONS: Administrative data can be used to estimate the prevalence of mental disorders in a pediatric population. The estimates made are lower than those obtained by using surveys of similar populations, perhaps indicating the difference between treated and untreated prevalence. Strengths of this study are that the estimates reflect the entire population, are more easily and obtained at less cost, and are useful for the planning of mental health services.

Geographic variations in the prevalence rates of Parkinson's disease in Alberta.

Parkinson's disease prevalence rates were examined for the Province of Alberta by age, sex and census division. Using the claims administrative data from the Alberta Health Care Insurance Plan, a cohort of all registered individuals (2.4 million) was extracted and followed for the five year period, April 1, 1984 to March 31, 1989. No new members were added to the cohort and an attrition rate averaging 6% per year was observed. The overall crude prevalence rates of 248.9 and 239.8 per 100,000 population were noted for males and females respectively. Both sexes were found to have a statistically significant variation across Alberta's 19 census divisions. For males, examination of standardized morbidity ratios found a low risk of Parkinson's disease associated with five census divisions, of which two contained Alberta's two largest cities. An excess risk was associated with four primarily rural census divisions. Females, on the other hand, had a low risk associated with one rural census division and excess risk in four census divisions. The uneven distribution within Alberta offers support for an environmental theory of etiology which may be associated with rural living.

Prevalence of cerebral palsy in Alberta.

BACKGROUND: In spite of scattered reports to the contrary, concern is continually expressed that the frequency of cerebral palsy has not decreased with modern perinatal/neonatal care. Overall, epidemiological information on cerebral palsy is scant. The generally accepted prevalence is 2 to 2.5 per thousand school-age children. METHODS: A population-based record linkage study of a presently living cohort of 96,359 children born from April, 1985 through March, 1988 and followed over an eight-year tracking period captured the diagnostic codes for all fee-for-service physician claims, all hospital separations and individual birth data from the Department of Vital Statistics of the Government of Alberta. The ICD-9 code "343" was used to identify subjects. The childhood prevalence and frequency by birthweight-specific sub-groups of cerebral palsy after age three years (congenital, 229 [92.3%]; probable acquired 19 [7.7%]) were identified giving an overall prevalence of 2.57 per 1000. Seventy percent were diagnosed before their third birthday. Cohort prevalence of cerebral palsy for low birthweight children (< 2500 grams) was 17.7, very low birthweight (< 1500 grams), 78.5; and extremely low birthweight (< 1000 grams), 98.4. Low birthweight children made up just over one-third of cases in this study. CONCLUSIONS: Cerebral palsy continues to affect a significant number of children suggesting the prevalence of cerebral palsy has not decreased. The proportion of affected children with low birthweight in this study is less than that reported in the literature.

The prevalence of motor neurone disease in the Province of Alberta.

Using data from the Alberta Health Care Insurance Plan, the prevalence of motor neurone disease (MND) was estimated for the Province of Alberta, Canada. Between January 1, 1994 and December 31, 1995, 208 cases of MND (125 males, 83 females) were identified from physician billing records giving a period prevalence of 7.38 (8.9 for males, 5.9 for females) per 100,000 population. On prevalence day, July 1, 1995, there were 171 cases (103 males, 68 females) of MND giving a point prevalence estimate of 6.07 (7.3 for males, 4.8 for females) per 100,000 population. Males were more likely to be diagnosed (OR = 1.52, 95% CI 1.1, 2.1) with MND and there was an increased risk of receiving a diagnosis with increasing age (chi 2trend = 281, p < 0.001). The mean age of the cases was 59.2 years (58.5 for males, 60.3 for females) and did not differ significantly between the sexes. Geographically, there was no statistically significant difference in the prevalence across regions of the Province. During the study period, 28% of the cases had died (30% of males, 25% of females). The prevalence of MND in Alberta, is among the highest reported in the literature and requires additional investigation to verify these estimates and identify possible causative factors.

Coronary artery bypass grafting in Alberta from 1984 to 1989.

OBJECTIVE: To examine the geographic and temporal trends in the performance of coronary artery bypass grafting (CABG) in the province of Alberta. This examination was designed to improve understanding of the geographic distribution and temporal changes in the incidence of the procedure. DESIGN: A cohort of all individuals (2.4 million) registered with the Alberta Health Care Insurance Plan (AHCIP) was followed for the five-year period from April 1, 1984 to March 31, 1989. No new members were admitted to the cohort and an attrition rate averaging 6% per year was observed. SETTING: Data from the claims administrative database of the AHCIP were used. The AHCIP includes the records of all registered residents of the province and is virtually complete. PARTICIPANTS: Participants included all 2963 members of the cohort (2413 males, 550 females) who underwent CABG over the study period. MAIN RESULTS: The overall mean surgical rate was 28.8 per 100,000 (46.7 for males, 10.8 for females; chi 2 = 1172.8, df = 1, P < 0.0001). The mean age at surgery was 59.6 years (57.9 for males, 61.4 for females), with 70 and 76% of procedures occurring between the ages of 60 and 70 years for males and females, respectively. The largest increases in incidence were in males (223%) and females (148%) aged 70 years or older. Both males (chi 2 linearity = 25.95, df = 3, P < 0.01) and females (chi 2 linearity = 8.34, df = 3, P < 0.05) displayed an increasing trend over the study period. Data were aggregated across the five-year study period to assess geographic variations. No difference was noted across census divisions for either sex. CONCLUSIONS: The similarity in rates across census divisions implies consistent use of criteria for the performance of this procedure. Also, the results imply that research, in Alberta, should focus more on indications for the procedure and its outcomes, than on geographic disparities.

Characteristics of preterm delivery and low birthweight among 113,994 infants in Alberta: 1994-1996.

This study examined the impact of infant and maternal factors on preterm delivery and low birthweight (LBW) in Alberta between January 1, 1994 and December 31, 1996. Data on 113,994 births were collected from vital statistics registration birth data. Logistic regression models for preterm and LBW delivery suggested the key risk factors were multiple and still birth (odds ratios > 22.0). Other characteristics included female gender, birth defects, nulliparous women, maternal age 35 and greater, unmarried, history of abortion, maternal smoking, maternal street drug use, and having less than 4 prenatal visits (odds ratios 0.86-2.54). Interactions between smoking and alcohol, and smoking and parity were noted. Efforts to improve the currently low rates (8.2%) of smoking cessation during pregnancy are required. Social, economic and medical factors associated with delayed childbearing and birth outcomes should be investigated.

Do area-based markers of poverty accurately measure personal poverty?

Area-based markers of deprivation (e.g., postal codes) are commonly used to identify groups of people with low socioeconomic status (SES); the validity of this approach, however, remains unknown. In this study, we determined the accuracy of using income quintile groups calculated on the basis of the median family income of each forward sortation area (1996 Canadian census) to identify those living in poverty (i.e., annual family income of < $12,620). The sensitivity and specificity of using the lowest income quintile to capture those in poverty were 26% and 83%, respectively (likelihood ratio (LR) of 1.49; 99% CI, 1.49 to 1.50). Among those in non-metropolitan and metropolitan areas, the LRs were 1.26 (99% CI, 1.26 to 1.27) and 2.01 (99% CI, 2.01 to 2.02), respectively. The use of postal codes as the only marker to identify people with low SES may result in substantial misclassification of personal poverty, particularly in non-metropolitan areas.

Sexually transmitted diseases and condoms: high school students' knowledge, attitudes and behaviours.

PIP: Researchers conducted a survey of 199 students enrolled 2 public high schools in Alberta in Canada to learn of their knowledge about sexually transmitted diseases (STDs) and knowledge, attitude, and behaviors about condoms and their use. 41% were sexually active. 41% of these students did not or rarely used condoms. 44% had =or+ 3 partners. 61% of those with =or+ 3 partners used condoms and 56% with 1 partner used them. Knowledge of STDs and condom use stood high regardless of sex or sexual activity. 93% of the boys, 80% of the girls, 88% of sexually active and 87% of nonsexually active students stated it was their responsibility to carry condoms if they are sexually active. Moreover 96% of the boys, 78% of the girls, 81% of sexually active and 91% of nonsexually active students said they would use a condom during sexual intercourse. Nevertheless males and sexually active students did express some negative attitudes towards condoms, such as reduce sensation and interference with sexual spontaneity. Nonsexually active students tended to view condom use as a negative stigma (p.05). Most students claimed to be more likely to buy condoms from condom vending machines in the rest rooms than from stores (p.05). Sexual partners had the largest influence on students, especially sexually active students, to have or not have sexual intercourse followed by concerns about STDs, friends, and family. Further, the large majority of all students, especially females and sexually active students, said they would choose their sexual partner carefully because of the concern for AIDS and other STDs. They also tended to be monogamous and avoided high risk groups. In conclusion, no reliable differences occurred between attitudes towards condoms and use or nonuse of condoms to explain behavior. Future studies should be designed to center on factors that influence sexual behavior.^ieng

Rural high school students' knowledge, attitudes and behaviours related to sexually transmitted diseases.

High school students are at high risk for contracting sexually transmitted diseases (STDs). A sample of 69 rural high school students from the province of Alberta, Canada were surveyed regarding their knowledge, attitudes and behaviours related to STDs to ascertain whether they differ from urban students. Results indicate that rural and urban high school students are similar in terms of knowledge about STDs, attitudes towards their prevention and also in terms of sexual behaviours. As with other studies, behaviours lagged behind knowledge and attitudes with reported condom use low. Sexual decision making was influenced mainly by the peer group. Males and females were mainly influenced by the same factors which include the willingness of their partner, the behaviours of their friends and family, concern about contracting a STD. These data emphasize the need to implement primary prevention programs for high school aged youth in rural as well as urban settings.