Saskatchewan Health

Abstract: OBJECTIVE: The purpose of this study was to determine the incidence of lactic acidosis in a geographically defined population of metformin users. RESEARCH DESIGN AND METHODS: The study was based on a historical cohort from the Saskatchewan Health administrative databases. Individuals with a metformin prescription dispensed between 1980 and 1995 inclusive were eligible for the cohort. Person-years of exposure were calculated. Cases were defined by hospital discharge with a diagnosis of acidosis (International Classification of Diseases, Ninth Revision code: 276.2) and confirmation by chart review of a blood lactate level > or = 5 mmol/l. Death registrations of individuals dying within 120 days of a metformin prescription were also reviewed. RESULTS: During the study period, 11,797 residents received one or more metformin prescriptions, resulting in 22,296 person-years of exposure. There were 10 subjects who had hospital discharges with a diagnosis of acidosis. However, primary record review revealed only two cases with laboratory findings of elevated blood lactate levels, for an incidence rate of 9 cases per 100,000 person-years of metformin exposure. In both cases, other factors besides metformin could have contributed to the lactic acidosis. No additional cases were found on review of death registrations. CONCLUSIONS: From 1980 through 1995, the incidence rate of lactic acidosis was 9 per 100,000 person-years (95% CI 0-21) in patients dispensed metformin in Saskatchewan, Canada. This incidence rate was derived from a population with complete ascertainment of hospitalizations and deaths associated with lactic acidosis in metformin users. It is similar to previously published rates based on passive reporting of cases, and it is well below the lactic acidosis rate of 40-64 per 100,000 patient-years in patients prescribed phenformin.

Abstract: Objective. —To examine the relationship between patterns of use of inhaled beclomethasone dipropionate and the risk of fatal and near-fatal asthma. Design. —Nested case-control analysis of a historical cohort; a further analysis. Setting. —The 12 301 residents of Saskatchewan aged 5 to 54 years who were dispensed 10 or more asthma drugs from 1978 to 1987. Patients. —The 129 persons who experienced asthma death (n=44) and near-death (n=85) and their 655 controls matched as to age and date of entry into the cohort, with the additional matching criteria of at least one hospitalization for asthma in the prior 2 years, region of residence, and having received social assistance. Main Outcome. —Life-threatening attacks of asthma defined as death due to asthma or the occurrence of hypercarbia, intubation, and mechanical ventilation during an acute attack of asthma. Results. —After accounting for the risk associated with use of other medications and adjustment for markers of risk of adverse events related to asthma, subjects who had been dispensed, on average, one or more metered-dose inhalers of beclomethasone per month over a 1-year period had a significantly lower risk of fatal and near-fatal asthma (odds ratio, 0.1; 95% confidence interval, 0.02 to 0.6). Conclusion.—These data support recent guidelines from several countries that recommend the use of inhaled corticosteroids in moderate and severe asthma. ( JAMA . 1992;268:3462-3464)

Abstract: PURPOSETo update key recommendations of the American Society of Clinical Oncology/College of American Pathologists estrogen (ER) and progesterone receptor (PgR) testing in breast cancer guideline.M...

Abstract: We carried out a nested case–control study to measure the rate ratio (RR) for invasive female breast cancer in relation to non-steroidal anti-inflammatory drug (NSAID) use. The source population consisted of the female beneficiaries of the Saskatchewan Prescription Drug Plan from 1981 to 1995 with no history of cancer since 1970. Four controls/case, matched on age and sampling time, were randomly selected. Dispensing rates during successive time periods characterized NSAID exposure. RRs associated with exposure during each period were adjusted for exposure during the others. Confounding by other determinants was studied in analyses adjusted with data obtained by interviewing samples of subjects accrued from mid-1991 to mid-1995. We accrued 5882 cases and 23 517 controls. Increasing NSAID exposure 2–5 years preceding diagnosis was associated with a trend towards a decreasing RR (P -trend = 0.003); for the highest exposure level RR = 0.76, 95% confidence interval 0.63–0.92. This protective effect could not be attributed to confounding by other determinants. In analyses involving only the cases, NSAID exposure 2–5 and 6–10 years preceding diagnosis was associated with significantly reduced risks of presenting with a large tumour (> 5 cm diameter) or distant metastasis, but not regional lymph node metastasis. The use of NSAIDs may retard the growth of breast cancers and prevent distant metastasis. © 2000 Cancer Research Campaign

Abstract: Summary: To measure the incidence of sudden unexplained death in treated persons with epilepsy (SUDEP) and to identify risk factors for SUDEP, a cohort of 6,044 persons aged 15–49 years with more than four prescriptions for antiepileptic drugs (AEDs) was identified from the Saskatchewan Health prescription drug file. To exclude subjects whose sudden deaths (SUDs) might be misattributed to another chronic underlying disease, subjects with hospitalizations for cancer or heart problems were excluded. To exclude subjects without epilepsy, subjects with >2-year AED treatment followed by AED-free time and subjects receiving < 1 U/day were excluded. The final cohort consisted of 3,688 subjects. Follow-up was started at the first AED prescription listed in the prescription drug file and ended at the earliest of the following: age 50 years, death, or last registration in the Saskatchewan Health. For 153 of 163 deaths occurring in the cohort, copies of anonymized death certificates were obtained and copies of anonymized autopsy reports of potential SUDEP cases were examined. There were 18 definite/probable SUDs and 21 possible SUDEPs, yielding a minimum incidence of 0.54 SUDEP per 1,000 person-years and a maximum of 1.35 SUDEP per 1,000 person-years. SUDEP incidence increased with male sex, number of AEDs ever prescribed, and prescription of psychotropic drugs and was highest in males with a history of treatment with three or more AEDs and four or more psychotropic drug prescriptions. Poisson regression showed a 1.7-fold increase in risk of SUDEP for each increment in maximum number of AEDs administered, a likely surrogate for severity and persistence of seizures.