Alberta Health Care Insurance Plan Research Articles

Risk of stroke within 3, 7, 14, 21 and 30 days after influenza vaccination in Alberta, Canada: A population-based study.

Influenza vaccination is associated with a longer-term protective effect against stroke; however, it has a short-term inflammatory response which may increase short-term risk of stroke. The aim was to investigate the association between influenza vaccination and short-term risk of stroke in adults. Administrative data were obtained from the Alberta Health Care Insurance Plan for all adults in Alberta, Canada, from September 2009 to December 2018. The hazard of any stroke (acute ischaemic stroke, intracerebral haemorrhage, subarachnoid haemorrhage and transient ischaemic attack) within 3, 7, 14, 21 and 30 days of influenza vaccination compared to unexposed time was analysed using Andersen-Gill Cox models, with adjustment for age, sex, anticoagulant use, atrial fibrillation, chronic obstructive pulmonary disease, diabetes, hypertension, income quintile, and rural or urban home location. In the entire cohort consisting of 4,141,209 adults (29,687,899 person-years), 1,769,565 (42.7%) individuals received at least one vaccination. In total 38,126 stroke events were recorded with 1309 occurring within 30 days of a vaccination event. Influenza vaccination was associated with a significantly reduced hazard of stroke within 3 days (hazard ratio [HR] 0.83, 95% confidence interval [CI] 0.73-0.93), 7 days (HR 0.87, 95% CI 0.80-0.95), 14 days (HR 0.87, 95% CI 0.81-0.93), 21 days (HR 0.85, 95% CI 0.80-0.91) and 30 days (HR 0.66, 95% CI 0.65-0.68). An increased early risk associated with vaccination was not observed. The risk of stroke was reduced at all time points within 30 days after influenza vaccination.

Association between influenza vaccination and risk of stroke in Alberta, Canada: a population-based study

Respiratory infection can be an immediate precursor to stroke and myocardial infarction. Influenza vaccination is associated with reduced risk of myocardial infarction and hospitalisation for cardiac disease, and influenza vaccination is strongly recommended for patients with heart disease. Evidence on whether the same protective association exists for stroke, and whether this potential effect is consistent across age and risk groups, is conflicting. We aimed to assess the risk of stroke after influenza vaccination in adults. We obtained administrative data from the Alberta Health Care Insurance Plan (which covers all residents of Alberta, Canada) beginning on Sept 30, 2009, or May 15 of the year in which residents were recorded as being 18 years of age. Individuals were censored at the earliest of three events: death, recorded outmigration, or Dec 31, 2018. The outcome of interest was any stroke event, comprising acute ischaemic stroke, intracerebral haemorrhage, subarachnoid haemorrhage, and transient ischaemic attack. We used Andersen-Gill Cox models to analyse the hazard of any stroke event for individuals with recent (<182 days) influenza vaccination compared with those without recent influenza vaccination, with adjustment for age, sex, anticoagulant use, atrial fibrillation, chronic obstructive pulmonary disease, diabetes, hypertension, income quintile, and rural or urban home location. Two-way interaction terms between each individual covariate and vaccination status were used to assess for effect modification by risk factor. The association between vaccination and risk of each type of stroke was also modelled, adjusting for baseline covariates. The study sample consisted of 4 141 209 adults (29 687 899 person-years of observation time) registered under the provincial health-care system between Sept 30, 2009, and Dec 31, 2018. 1 769 565 (42·73%) individuals received at least one vaccination during the study period, and 38 126 stroke events were recorded. Adjusted for demographics and comorbidities, recent influenza vaccination significantly reduced the hazard of stroke (hazard ratio 0·775 [95% CI 0·757-0·793]). This association persisted across all stroke types. We found effect modification by each covariate examined except for home location; however, vaccination was associated with a reduced risk of stroke overall across all ages and risk profiles with the exception of individuals without hypertension. The risk of stroke is reduced among people who have recently been vaccinated against influenza compared with those who have not. This association extended to the entire adult population and was not limited to individuals with a baseline high risk of stroke. Further studies in a variety of settings are needed to evaluate whether influenza vaccination could be used as a public health strategy to prevent stroke. None.

A155 REAL-WORLD USE OF CORTIMENT IN ULCERATIVE COLITIS: A POPULATION-BASED STUDY

Abstract Background Ulcerative colitis (UC) is a relapsing and remitting disease with variable severity. BudesonideMMX (Cortiment®) was approved by Health Canada for the treatment of mild to moderate UC in July 2016. It offers the advantage of extensive first pass hepatic metabolism resulting in decreased systemic corticosteroid toxicity. Most public drug plans in Canada do not cover it, limiting its use to private insurance and self-pay. Aims To characterize the UC patients who use Cortiment® and explore prescribing patterns and short-term outcomes. Methods Population-based administrative data identified patients who were covered by the Alberta Health Care Insurance Plan and dispensed Cortiment® from August 1, 2016 to December 31, 2017. Analyses identified: age, sex, rural/urban status, Material [MDI] and Social Deprivation Indices [SDI], UC-related medications 6-months before and 10-weeks following Cortiment® dispensing, and disease exacerbation indicators (new dispense of corticosteroids, hospitalization with inflammatory bowel disease (IBD) as most responsible diagnosis, or IBD-related surgery). Results We identified 427 UC patients dispensed Cortiment®. The median age was 47 years (25th %: 35; 75th %: 59) and 57.4% were females. Most individuals (91.3%, n=390) resided in an urban setting, as compared to approximately 73% of all UC cases. Distribution of patients across SDI was consistent while the MDI had a higher proportion in the more well-off categories. 77.5% had a UC-related drug therapy in the 6 months prior to Cortiment® dispensing and 71.7% had a UC-related drug dispensed in the 10-weeks following. Approximately, 30% had a disease exacerbation indicators in the 10 weeks following dispensing: 24.8% new corticosteroid, 3.7% UC-related hospitalization, and <2.3% UC-related surgery. Conclusions Despite lack of public drug coverage, Cortiment® was dispensed across socioeconomic classes. The high dispensing within urban sites suggests that rural UC patients may have less access to Cortiment®. While a quarter of Cortiment® dispensings had a new concurrent dispensing of prednisone, <5% of these patients were admitted to hospital for a flare of UC. Funding Agencies Ferring Pharmaceuticals

Existing comorbidities in people with osteoarthritis: a retrospective analysis of a population-based cohort in Alberta, Canada

ObjectivesThe purpose of this study is to estimate the prevalence of comorbidities among people with osteoarthritis (OA) using administrative health data.DesignRetrospective cohort analysis.SettingAll residents in the province of Alberta, Canada...

Utilization and Costs of Noninvasive Cardiac Tests After Acute Coronary Syndromes: Insights From the Alberta COAPT Study

BackgroundAlthough appropriate noninvasive cardiac tests (NICTs) after an acute coronary syndrome (ACS) provide useful prognostic information, inappropriate use leads to inefficient expenditure of existing healthcare resources. By using the Alberta Contemporary Acute Coronary Syndrome Patient Invasive Treatment Strategies (COAPT) Registry, we evaluated the use and costs of NICTs among patients discharged within 1 year after ACS. MethodsAll patients discharged from the hospital with a primary diagnosis of ACS in Alberta between 2004/2005 and 2015/2016 were included. Frequency of NICTs (stress tests [± imaging] and nonstress imaging tests) was determined from linked provincial databases. Costs were obtained from the Alberta Health Care Insurance Plan Medical Procedure List. ResultsOf 55,516 patients with ACS, 30,760 had at least 1 NICT (55.4%), with 13,505 (24.3%) having > 1 NICT performed within 1 year. Temporal trends of NICT increased over time (stress tests: P trend < 0.001; nonstress imaging tests: P trend < 0.001). NICT most commonly occurred within the first 4 months after hospital discharge (stress tests at 2 months; nonstress imaging tests at 3-4 months). In 2015/2016, the total estimated costs of NICT were $1.35M, a 22.4% increase from 2004/2005 (1.10M) (P < 0.001), whereas a decrease in incidence of ACS over the same time period was noted (P = 0.008). ConclusionsRates of NICT 1 year after ACS are high and increasing over time. Estimated costs of NICT appear to be escalating out of proportion to the ACS growth. Further investigation is warranted because it is speculative whether the increase in NICT and costs results in clinical benefit after ACS.

Real-world incidence and prevalence of systemic lupus erythematosus in Alberta, Canada

Systemic lupus erythematosus (SLE) is rather uncommon than rare. The purpose of this study was to estimate the incidence and prevalence of SLE in the population of Alberta, Canada, using administrative health data. Multiple population-based data sources, including the Alberta Health Care Insurance Plan Central Stakeholder Registry (AHCIP CSR), Fee-For-Service, and Hospital Discharge Database were used. Age- and sex-specific incidence and prevalence rates, and 95% confidence intervals (CI), were computed using the AHCIP CSR mid-year population estimates as the denominator, for the period of 2000–2015. The overall incidence of SLE for all age groups was 4.43 (95% CI 3.65, 5.04) per 100,000 population. The overall incidence in male and female of all age groups was 1.26 (95% CI 0.72, 1.76) and 7.69 (95% CI 6.22, 8.81) per 100,000 population, respectively. A prevalence of 47.99 per 100,000 (male = 13.5, female = 83.2) of SLE was observed for the year 2000 and has increased to 90 (male = 25.5, female = 156.7) per 100,000 population in 2015. Over the 16-year period, the incidence of SLE in women was approximately six times higher than in men (odds ratio = 6.16). The highest and lowest incidence was recorded in 2001 and 2015, respectively. Despite the stable incidence of SLE, the findings of the study confirms that the prevalence of SLE has increased over the 16-year period. The increase in prevalence of SLE in Alberta will have an impact on health service utilizations. This finding can be used for planning and evaluating health services for this group of patients. Further studies are required to determine the economic burden of the condition.

The effectiveness of shingles vaccine among Albertans aged 50 years or older: A retrospective cohort study.

We assessed the effectiveness of shingles vaccine in preventing incident shingles among Alberta residents aged 50 years or older over the period 2009 - 2015, using administrative health data. The cohort comprised of Albertans from the Alberta Health Care Insurance Plan Registry (AHCIP) as of June 30, 2009 and aged 50 years or older. Those who received shingles vaccine were identified from the provincial pharmaceutical information network. The occurrence of incident shingles was identified through both inpatient and outpatients/community care data. Incident shingles was defined as the earliest dated record of ICD 9-CM 053 or ICD-10-CA B02. Starting on November 1, 2009, individuals with no history of shingles or shingles vaccination were followed until Nov 1, 2015 (6 years), or until shingles incidence, death, or AHCIP cancellation (including leaving Alberta). Vaccine effectiveness (VE) was estimated as the inverse of the relative risk of developing incident shingles in each year following vaccination compared to time at risk without vaccination, while adjusting for age, sex, income quintile, and immune compromising conditions (identified from physician claims, inpatient, and cancer registry data). There were 1,094,236 individuals in the cohort, with 85,439 (7.80%) vaccinated individuals. The shingles incidence rate was 9.03 [95% CI: 8.95, 9.11] cases per 1,000 person years (49,243 cases). Adjusted VE in the first year following immunization was 50.02% [95% CI: 44.71%, 54.83%] against incident shingles, decreasing to no effect by the fifth year (VE = 14.00% [95% CI: -20.99%, 38.88%]). Our findings are consistent with observations from other population based studies and provide population level data for policy-makers to review when making decisions related to public funding of shingles vaccine.

Impacts of Alternative Billing Claims on Hypertension Prevalence and Mortality Estimates in Alberta, Canada

ABSTRACT&#x0D; ObjectivesIn Canada, secondary sources of health information such as physician billing claims are used for surveillance of chronic conditions such as hypertension. The value of this data may be affected by different types of physician payment models. Fee-for-service (FFS) physicians submit billing claims in order to be remunerated whereas physicians on salary or capitation also called alternative payment plans (APP) are remunerated regardless of whether claims are submitted. Thus there are concerns nationally that APPs may be associated with decreased frequency of billing submission, thereby eroding data quality and leading to underestimates of disease burdens and outcomes. We assessed the impact of APPs on hypertension prevalence, mortality and cardiovascular (CVD) hospitalization in Alberta.&#x0D; ApproachThe following health administrative databases from Alberta, Canada were used in this study: 1) Alberta Health Care Insurance Plan registry; 2) Hospital Discharge Abstract database (DAD); 3) Physician claims data and; 4) Vital Statistics database. We defined patients with hypertension aged 20 years and older between April 1, 2004 and March 31, 2009 (fiscal years 2004 to 2009) based on previously validated algorithm. Cases were then sorted into FFS and non-FFS billing status. Descriptive statistics for age group, sex, income quintile, rural/urban geographical location, death status and comorbidities were reported between the shadow billing and non-shadow billing groups in regards to prevalence, all-cause mortality and CVD hospitalizations.&#x0D; ResultsA total of 613, 844 adult hypertensive cases were captured during the 5 year study period. The majority of hypertension cases (99.6%, n=610,167) were identified through FFS claims. The effect of non-FFS billing estimates represented a small proportion of hypertension cases (0.40%, n=3677) identified during the study period. Among the FFS claims, overall hypertension prevalence was 22.2% (n=610167) and the effect of non-FFS billing estimates (0.13%, n=3677) on prevalence estimates was relatively minor. All-cause mortality 33.8 (95% CI 33.6-34) and CVD 40.6 (40.4-40.9) were higher for FFS cases than non-FFS cases 19.0 (16.6-21.8) and CVD: 8.0 (6.4-9.8).&#x0D; ConclusionDuring the study time period, the impact of non-FFS (i.e. shadow billings) on physician claims may not have impacted hypertension prevalence estimates greatly. Since Alberta uses shadow billing incentive programs, future research is needed to determine whether incentive programs should be considered in other provinces or nationally in order to preserve the overall quality of physician claims data.

Cancer incidence and mortality among the Métis population of Alberta, Canada

BackgroundCancer has been identified as a major cause of morbidity and mortality in Canada over the last decade. However, there is a paucity of information about cancer patterns in Aboriginal people, particularly for Métis. This study aims to explore cancer incidence and mortality burden among Métis and to compare disease estimates with non-Métis population.MethodsThis population-based descriptive epidemiological study used cancer incidence and mortality data from 2007 to 2012 obtained from Alberta Health Care Insurance Plan (AHCIP) – Central Stakeholder Registry – and Alberta Cancer Registry (ACR). To identify cancer cases in Métis, the ACR was linked with the Métis Nation of Alberta (MNA) Identification Registry. In Métis and non-Métis people, age-standardized cancer incidence and mortality rates were estimated and subsequently compared between both groups.ResultsA higher incidence of bronchus/lung cancer was found among Métis men compared with their non-Métis counterparts (RR=1.69, CI 1.28–2.09; p=0.01). No other statistically significant differences in cancer incidence or mortality were found between Métis and non-Métis people living in Alberta over the course of the 6 years studied.ConclusionsOverall incidence and mortality associated with cancer were not higher among Métis people compared with non-Métis people. However, special efforts should be considered to decrease the higher incidence of bronchus/lung cancer in Métis men. Further development and maintenance of new and existing institutional collaborations are necessary to continue cancer research and health status surveillance in Métis population.

Geographic clustering of emergency department presentations for atrial fibrillation and flutter in Alberta, Canada.

Atrial fibrillation and flutter (AFF) are the most common arrhythmias seen in the outpatient setting, and they affect more than 300,000 adult Canadians. The aims of this study were to examine temporal and geographic trends in emergency department (ED) presentations made by adults (age ≥ 35 years) for AFF in Alberta, Canada, from 1999 to 2011. Statistical disease cluster detection techniques were used to identify geographic areas with higher numbers of individuals presenting with AFF and higher numbers of ED presentations for AFF than expected by chance alone. Geographic clusters of individuals with stroke or heart failure follow-up within 365 days of ED presentations for AFF were also identified. All ED presentations for AFF made by individuals aged ≥35 years were extracted from Alberta's Ambulatory Care Classification System. The Alberta Health Care Insurance Plan provided population counts and demographics for the patients presenting (age, sex, year, geographic unit). The Physician Claims File provided non-ED physician claims data after a patient's ED presentation. Statistical analyses included numerical and graphical summaries, directly standardized rates, and statistical disease cluster detection tests. During 12 years, there were 63,395 ED presentations for AFF made by 32,101 individuals. Standardized rates remained relatively stable over time, at about two per 1,000 for individuals presenting to the ED for AFF and about three per 1,000 for ED presentations for AFF. The northern and southeastern parts of the province were identified as clusters of individuals presenting for AFF, and ED presentations for AFF, and several of the areas demonstrated clusters in multiple years. Further, several of the geographic clusters were also identified as potential clusters for stroke or heart failure within 365 days after the ED presentations for AFF. This population-based study spanned 12 fiscal years and showed variations in the number of people presenting to EDs for AFF and the number of ED presentations for AFF over geography. The potential clusters identified may represent geographic areas with higher disease severity or a lower availability of non-ED health services. The clusters are not all likely to have occurred by chance, and further investigation and intervention could occur to reduce ED presentations for AFF.

Imbalance of prevalence and specialty care for osteoarthritis for first nations people in Alberta, Canada.

To estimate the population-based prevalence and healthcare use for osteoarthritis (OA) by First Nations (FN) and non-First Nations (non-FN) in Alberta, Canada. A cohort of adults with OA (≥ 2 physician claims in 2 yrs or 1 hospitalization with ICD-9-Clinical Modification code 715x or ICD-10-Canadian Adaptation code M15-19, 1993-2010) was defined with FN determination by premium payer status. Prevalence rates (2007/8) were estimated from the cohort and the population registered with the Alberta Health Care Insurance Plan. Rates of outpatient primary care and specialist visits (orthopedics, rheumatology, internal medicine), arthroplasty (hip and knee), and all-cause hospitalization were estimated. OA prevalence in FN was twice that of the non-FN population [16.1 vs 7.8 cases/100 population, standardized rate ratio (SRR) adjusted for age and sex 2.06, 95% CI 2.00-2.12]. The SRR (adjusted for age, sex, and location of residence) for primary care visits for OA was nearly double in FN compared with non-FN (SRR 1.88, 95% CI 1.87-1.89), and internal medicine visits were increased (SRR 1.25, 95% CI 1.25-1.26). Visit rates with an orthopedic surgeon (SRR 0.49, 95% CI 0.48-0.50) or rheumatologist (SRR 0.62, 95% CI 0.62-0.63) were substantially lower in FN with OA. Hip and knee arthroplasties were performed less frequently in FN with OA (SRR 0.48, 95% CI 0.47-0.49), but all-cause hospitalization rates were higher (SRR 1.59, 95% CI 1.58-1.60). We estimate a 2-fold higher prevalence of OA in the FN population with differential healthcare use. Reasons for higher use of primary care and lower use of specialty services and arthroplasty compared with the general population are not yet understood.

Herpes zoster vaccine (HZV): utilization and coverage 2009 - 2013, Alberta, Canada.

BackgroundHerpes zoster vaccine (HZV) is not publicly funded in the province of Alberta, Canada. We estimated vaccine coverage among those aged 60 years or older for 2013, as well as vaccine utilization rates per hundred thousand population over the period 2009 – 2013. We explored for factors associated with HZV dispensing rates.MethodsWe used administrative data from the Alberta Pharmaceutical Information Network (PIN) database to identify unique persons for whom HZV had been dispensed from community pharmacies over 2009 – 2013. PIN data were also used to estimate the pharmacy/population ratios for rural and urban Alberta over the period. Denominators for rates were estimated using mid-year population estimates from the Alberta Health Care Insurance Plan Registry. Income quintile data were estimated from the 2006 Census of Canada. Crude, age, sex, geographic (rural vs. urban), income-quintile and year specific rates of HZV vaccine dispensing were estimated per 100,000 population. Rates were adjusted for pharmacy/population ratio. Vaccine coverage for persons aged 60 years or older was estimated using counts of all unique persons for whom the vaccine was dispensed over the period in the numerator and a 2013 mid- year population denominator.ResultsHZV dispensing rates rose annually from 2009 – 2013. Vaccine coverage was estimated to be 8.4% among persons aged 60 years or older. Rates of dispensing were highest for persons aged 60–69 years and were higher for females than males and for persons from higher compared to lower income quintiles. Dispensing rates were lower for rural than for urban residents. About 2% of vaccine was dispensed for persons aged less than 50 years.ConclusionsRates of HZV dispensing are increasing rapidly in Alberta despite a lack of public funding. A small proportion of the vaccine may be dispensed off-label.

Shingles in Alberta: Before and after publicly funded varicella vaccination

Purpose: A universal publicly funded chickenpox vaccination program was implemented in Alberta in 2002. We examine the epidemiology of medically attended shingles in Alberta from 1994 to 2010.Methods: Incident shingles cases (earliest health service utilizations for ICD-9 053 or ICD-10-CA B02) and their co-morbid conditions for the 12 months prior to shingles diagnosis were identified from the records of Alberta's universal, publicly funded health-care insurance system for 1994–2010. Shingles diagnostic codes at least 180 days after the first were classified as recurrent episodes. Denominators for rates were estimated using mid-year population estimates from the Alberta Health Care Insurance Plan Registry. Annual age- and sex-specific rates were estimated. We estimated the proportion of all cases that were hospitalized. We explored the pattern of rates for sex, age-group co-morbidity and year effects and their interactions.Results: Crude rates of shingles increased over the interval 1994–2010. Most persons had only a single episode of shingles; 4% of cases were hospitalized. Shingles rates were higher among females than males. While only 2% of shingles cases had one or more co-morbidities, this proportion was also higher for females than males. Prior to 2002, all age groups of both sexes experienced increasing annual rates of shingles. However, there was a sharp decline in the rate of shingles for both females and males under the age of 10 years for 2002–2010, the period in which there was publicly funded chickenpox vaccination.Conclusion: The declining rates of shingles among persons under the age of 10 years are consistent with an impact of the chickenpox vaccination program. The trend of increasing rates of shingles among older persons began prior to implementation of vaccination.

Human Rights, Transsexed Bodies, and Health Care in Canada: What Counts as Legal Protection?

AbstractAntidiscrimination legislation is the vehicle most commonly used by communities to demand equality, but how should such law best be employed? In this article, the Ontario Human Rights Tribunal decision inHogan v. Ontario (Health and Long-term Care)is examined in relation to the removal of sex reassignment surgery from the Alberta Healthcare Insurance Plan in order to better understand the legal strategies designed to remedy different kinds of discrimination. This article argues that trans issues (involving people who identify as transgender, transsexual, or trans) ought not to be seen as additions to gay and lesbian issues legally or politically. Moreover, this article demonstrates that the fight for formal inclusion in legislation as a discrete or insular minority should be rejected by trans activists, as other legal strategies are better positioned to combat the processes of transphobia, thus potentially offering important steps towards substantive equality.

Contribution of incidence to increasing prevalence of multiple sclerosis in Alberta, Canada

Alberta Health Care Insurance Plan (AHCIP) data were used to calculate prevalence and incidence rates for multiple sclerosis (MS) in the general population of Alberta from 1990 to 2004. Multiple sclerosis prevalence rose steadily each year over this time period, from 217.6/100,000 individuals in 1990 to 357.6/100,000 in 2004. Multiple sclerosis incidence fluctuated with a slight increase from 1990 to 2004, at 20.9/100,000 and 23.9/100,000, respectively. Age-specific prevalence rates were higher between ages 30 and 60 in 2004 than in 1990. The pattern of age-specific incidence rates was similar in 1990 and 2004, with a slight shift toward diagnosis in younger years. Gender-specific prevalence rates were higher for females in both 1990 and 2004, with a greater increase in females (43%) than males (29%). Gender-specific incidence rates were higher for females than males in both years, but there was no differential increase in incidence by gender from 1990 to 2004. The 2004 Alberta MS prevalence rate remains among the highest reported worldwide. Both increasing incidence and longer duration have likely contributed to increasing MS prevalence in the province.

Secular trends in the epidemiology of shingles in Alberta

Varicella vaccine was licensed in Canada in 1998, and a publicly funded vaccination programme introduced in the province of Alberta in 2001. In theory the vaccination programme might increase the burden of disease from shingles, making it important to develop baseline data against which future comparisons can be made. The study's aim was to describe the epidemiology of non-fatal cases of shingles for which publicly funded health services were utilized for the period 1986-2002. Shingles cases were identified from the records of Alberta's universal, publicly funded health-care insurance system for 1986-2002. The earliest dated health service utilizations for ICD-9-CM codes of 053 or ICD-10-CA codes of B02 were classified as incident. Diagnostic codes at least 180 days after the first were classified as recurrent episodes. Denominators for rates were estimated using mid-year population estimates from the Alberta Health Care Insurance Plan Registry. Annual age- and sex-specific rates were estimated. We explored the pattern of rates for sex, age and year effects and their interactions. Shingles rates increased between 1986 and 2002. There was a sex effect and evidence of an age-sex interaction. Females had higher rates than males at every age; however, the difference between females and males was greatest for the 50-54 years age group and declined for older age groups. The increased rate of shingles in Alberta began before varicella vaccine was licensed or publicly funded in Alberta, and thus cannot be attributed to vaccination.

Chronic Disease Score as a covariate of multiple regression models

Purpose Derive the Chronic Disease Score (CDS) as a covariate of the multiple regression models for comorbidity adjustment with automated pharmacy data in Alberta, Canada. Methods Different types of medications prescribed during 2001/2 for the treatment and management of chronic conditions were obtained from Alberta Blue Cross (ABC) claims database. The medications were clustered into 25 therapeutic classes to indicate the presence of a chronic illness based on the criteria proposed by Clark et al in 1995. The study population was composed of all Alberta residents aged 65 or over who were registered with the Alberta Health Care Insurance Plan (AHCIP) continuously from 2001/2 to 2002/3. Individuals who terminated the registry before March 31, 2003 were included if they had been admitted to hospitals in 2002/3. Individuals were excluded if they had been diagnosed with any malignancy, tuberculosis or HIV during 2001/2 and 2002/3. Medications used in the direct treatment of these diseases are provided by other health insurance agencies instead of ABC. Hospitalization rate in 2002/3 was derived from AHCIP databases. Logistic regression models were utilized to estimate CDS scores. The CDS developed by Clark et al was replicated with Alberta Data. Its validity was compared with that of the proposed CDS. Results Records for 216,724 seniors were used to estimate the empirical weights for calculating CDS. Odds ratios for hospitalization from predicted CDS increased with each percentile group. The risk of hospitalization increased 12-fold for persons with a predicted score in the 90th–100th percentile over those in the 0 th –10th percentile. It was higher than those devised from any of the 3 CDS scores with cost or utilization weights. Conclusion CDS can be generally used as a combined covariate to adjust morbidity rates for different populations. To improve the validity of the adjustment, the weights of CDS should be estimated using the morbidity (hospitalization for this study) rate itself as the dependent variable of the regression model.

Descriptive Epidemiology of Affective Disorders in Multiple Sclerosis

Affective disorders present an important clinical challenge in multiple sclerosis (MS). Due to prohibitive sample size requirements, population-based studies have not yet provided an adequate description of the underlying epidemiology of this association. To describe the epidemiology of affective disorders in MS in a general population sample. The study presented here accessed administrative data from a universal healthcare insurance plan in the Canadian province of Alberta. Physician billing data recorded in the Alberta Health Care Insurance Plan was used to identify members of the population >15 years of age with and without MS. Crude and stratified estimates of the association between affective disorders and MS were made. Logistic regression analysis was used to evaluate statistical interactions and to provide adjusted estimates of the association. The estimated prevalence of MS in the population within the targeted age range (2.3 million individuals) was 386/100,000 and that of affective disorders was 7.7%. As expected, an association between MS and affective disorders was identified (crude relative prevalence: 2.2). The association varied in strength over age-sex categories. Although the prevalence of affective disorder was higher in women with MS than men with MS, the association of MS with affective disorders was stronger in men. The strength of association declined with age in both men and women. Affective disorder prevalence in people with MS becomes similar to that of the general population in older age groups. Affective disorders occur with an increased frequency in MS. This is true in men and women and across all relevant age groups, although the association gets weaker with advancing age. Higher frequencies of affective disorder occur in women with MS than in men with MS. The frequency of affective disorder in people with MS is highest in the 25-44 age group, and declines in older age categories.

Prevalence of NSAID use among Alberta seniors in 2002–2003

Purpose To describe the prevalence of nonsteroidal anti-inflammatory drug (NSAID) use, including COX-2 inhibitors, among patients 65 years of age or older in Alberta, Canada. Methods Records of all patients 65 and older who were prescribed NSAIDs were extracted from the 2002 to 2003 Alberta Blue Cross (ABC) administrative database, which included Drug Identification Number (DIN), prescribed drug quantity, patient's gender and birth date. Age–gender distribution of 2002 mid-year Alberta population was extracted from the Alberta Health Care Insurance Plan (AHCIP) registry file. Drug unit prices were obtained from the 2003 Alberta Health and Wellness Drug Benefit List. Age- and gender-specific prevalence rates and costs of the overall NSAID and COX-2 uses were calculated with these data. Results A total of 87,153 seniors were prescribed NSAIDs. Of these, 59,502 were prescribed at least one type of COX-2 (33,579 celecoxib; 30,060 rofecoxib). Crude prevalence of overall NSAID and COX-2 uses were 27.0% and 18.5%, respectively. Annual costs for the overall NSAIDs and COX-2 were C$17.3 × 10 6 and C$14.5 × 10 6 , respectively. Women used NSAIDs more than men (1.49 times in number and 1.76 in cost). Women aged 75 to 79 had the highest prevalence of NSAID use (31.4%). Among men the highest prevalence was in the 70 to 74 age category (25.8%). Restricted to COX-2, the highest prevalence in the 75 to 79 age category was 23.1% for women and 16.5% for men. Conclusion Pain is a common symptom among people aged 65 and over. NSAIDs are general therapies for symptomatic pain. The use of NSAIDs is clearly increasing in the aging population. In 2002 to 2003, more than one fourth of Alberta seniors used NSAIDs, which is higher than previously reported.

Patterns of injury in children: a population-based approach.

We describe the frequency and patterns of injury affecting 96 359 children between 0 and 10 years old and living in Alberta, Canada. This population-based, longitudinal study involved children born in the 3 fiscal years of April 1, 1985 to March 31, 1988, recruited before age 1, and who remained in the study until at least age 5. We used the International Classification of Diseases, Ninth Revision, Clinical Modification chapter-17 diagnostic codes provided by physicians. Codes were grouped into 17 categories; injury episodes were calculated, and age- and gender-specific incidence rates for each category were calculated. The age, pattern, times of greatest risk, and the effect of gender on the type and incidence of injury were determined. Health care administrative data were obtained from all fee-for-service health care venues in Alberta between April 1, 1985 and March 31, 1998 providing services to children registered with the Alberta Health Care Insurance Plan and otherwise meeting entrance criteria. Nearly 84% of children received care for an injury during the study period, and in any given year approximately 21% of the population studied had at least 1 injury. Repeat injury was common (73%), and boys were more likely than girls to be injured and to have repeat injury. The most common injuries were dislocations and sprains, open wounds, and superficial injuries and contusions. Burns, poisoning, intracranial injury, and foreign bodies were the next most common, and fractures were least common. Approximately 10% of injuries were multiple-category injuries. Rates varied greatly by injury category, age, and gender. Hospitalization rates varied in a similar manner and commonly accounted for approximately 10% of all services. Males were most likely to have an injury, and aboriginal children or children who had received welfare at some time were at greatest risk. Administrative data can be used to estimate the incidence of injury in a pediatric population. Distinct patterns of injury occur at different ages. Recurrent injury is common. Almost identical proportions of injury (46%) are treated in emergency departments and physicians' offices.