Quebec Residents Research Articles

Selective Serotonin Reuptake Inhibitors and the Risk of Cataracts: A Nested Case-Control Study

Older-generation antidepressants have been associated with increasing the risk of cataracts. Although animal studies have alluded to a potential link between selective serotonin reuptake inhibitors (SSRIs) and the development of cataracts, no large population based-study has addressed this potential association. This study sought to quantify the risk of cataracts with SSRIs by conducting a pharmacoepidemiologic study using the linked administrative databases in the province of Quebec, Canada. Nested case-control study. A cohort of subjects who had received a coronary revascularization procedure from 1995 through 2004 in the province of Quebec, Canada. Using an administrative data set, a case-control study was conducted within a cohort of Quebec residents who had received a coronary revascularization procedure from 1995 through 2004. Cases were defined as those with the first diagnosis of a cataract diagnosed by an ophthalmologist. For each case, 10 controls were selected and matched to the cases by index date, age, and cohort entry. Crude and adjusted rate ratios (RRs) and corresponding confidence intervals (CIs) were computed for current use of SSRIs. Rate ratios were adjusted for gender, corticosteroid use, statins, high blood pressure, antihypertensives, and antidiabetics. First International Classification for Disease (Ninth Revision) code for a cataract diagnosed by an ophthalmologist. Eighteen thousand seven hundred eighty-four cases and 187 840 controls met our study inclusion criteria. The adjusted RR for cataracts among current users of SSRIs was 1.15 (95% CI, 1.08-1.23). The risk of cataracts was highest with fluvoxamine (RR, 1.39; 95% CI, 1.07-1.80), followed by venlafaxine (RR, 1.33; 95% CI, 1.14-1.55) and paroxetine for cataract surgery (RR, 1.23; 95% CI, 1.05-1.45). The average time to diagnosis of cataracts while on SSRI therapy was 656 days. A possible association was found between current exposure to SSRIs, especially fluvoxamine and venlafaxine, and a future diagnosis of cataracts. The possibility that this observation may be the result of the effect of smoking, which could not be controlled for in the study, cannot be excluded. Future studies are needed to confirm this association in other populations.

The Evolution of Amputation in the Province of Quebec

ABSTRACT OBJECTIVE: Lower-extremity amputation rate is often used as an indicator of the quality of diabetes care. This study provides a long-term perspective on amputation in the Quebec population, estimating changes over time in rates of vascular amputation and comorbidity profile. METHODS: A population-based admission-to-discharge cohort study was conducted using hospital discharge data. The population consisted of all Quebec residents having an amputation from January 1, 1996, to December 31, 2004. The reason for amputation was defined by diagnostic code; the level of amputation was identified by treatment code; and the proportion of people with specific comorbidities was calculated for each year. Age-and sex-specific rates of amputation were calculated. RESULTS: A total of 10 834 people had 15 992 amputations. Of these people, 79% had vascular disease. Within this population, hypertension has increased by 27.2% (95% CI 22.9-31.6), renal disease by 14.9% (95% CI 11.1-18.7) and ischemic heart disease by 20.4% (95% CI 16.3-24.4). Length of hospital stay did not change over time; the median length of stay was 20 days (IQR: 8.5, 40, 658). Women having foot amputations, people having multiple amputations or people with a high Charlson index score were more likely to stay in hospital for more than 28 days. A linear decrease in the rate of vascular and diabetic amputations was observed for both men and women, with the greatest decrease being 8.1% (95% CI 5.8-10.4) among males with vascular disease. INTERPRETATION: Despite the decline in sex-specific, agestandardized rates of amputation, there was no decrease in the number of amputations being performed; this may reflect the increased prevalence of diabetes and standard of care being given. The implication for the changing profile of people having amputations are great: for example, post-amputation care needs to address the multiple comorbidities.

Effect of Statin Adherence on Cerebrovascular Disease in Primary Prevention

Background Evidence from meta-analyses shows that statin therapy reduces all-cause mortality and nonhemorrhagic strokes. Nonadherence to statins may reduce this protective effect. The association between statin adherence and incidence of cerebrovascular disease remains unexplored outside the context of clinical trials. Objective To evaluate the impact of statin adherence on the occurrence of cerebrovascular disease in a real clinical setting. Methods A cohort of 112,092 patients was reconstructed using the Régie d'assurance maladie du Québec and Med-Echo databases. The Régie d'assurance maladie du Québec database contains information from 3 types of health-related data, such as demographic information, medical data, and the prescription claims file. The Med-Echo database contains data on acute care hospitalizations on all Quebec residents. All patients without cardiovascular disease aged 45-85 years who were newly treated with statins between 1999 and 2004 were eligible. A nested case-control design was used to study the occurrence of cerebrovascular disease. Adherence level was reported as a medication possession ratio. Conditional logistic regression models were used to estimate the rate ratio of cerebrovascular disease, adjusting for different covariables. Results The mean patient age was 63 years; 49% had hypertension, 21% had diabetes, and 41% were males. Nonadherence was prevalent because only 55% of the patients were exposed to ≥80% of the medication during follow-up. We did not observe any major differences, defined as more than 5%, between the groups, except for the sex, diabetes, and hypertension. High level of adherence to statins was associated with a reduction of cerebrovascular events (rate ratio: 0.74; 95% confidence interval, 0.65-0.84). Conclusions Our study suggests a relatively low level of adherence to statins, but more importantly, that adherence is associated with a risk reduction for cerebrovascular disease. Adherence to statin therapy needs to be improved, so that patients can benefit from the full protective effects of statin therapy.

Risk of upper gastrointestinal bleeding with oral bisphosphonates and non steroidal anti‐inflammatory drugs: a case‐control study

Gastrointestinal injuries including gastric ulcers have been reported with oral bisphosphonate therapy. However, the risk of the more serious upper gastrointestinal bleeding (UGB) especially in the community setting with these drugs remains unknown. Similarly, the risk of UGB among users of both bisphosphonates and non steroidal anti-inflammatory drugs (NSAIDs) in the community is also unknown. To explore the risk of more serious UGB among users of bisphosphonates and the risk of UGB among users of both bisphosphonates and NSAIDs in the community. We conducted a case-control study within a cohort of Quebec residents who had received a revascularization procedure from 1995 to 2004. Cohort members were followed up from the date of their first procedure until the earliest of: (1) study outcome, (2) date of death or (3) end of health care coverage. Cases were defined as those with the first diagnosis of a UGB. For each case, 20 controls were selected and matched to the cases by index date, age and cohort entry. Adjusted odds ratios for current use of bisphosphonates, NSAIDs and co-therapy of both drugs were computed. Within the initial cohort, 3253 incident cases of UGBs and corresponding 65 060 matched controls were identified. The adjusted odds ratio (OR) for UGB by current users of bisphosphonates was 1.01 (95% CI, 0.72-1.43). Current NSAID use was associated with an increased risk of UGB OR = 1.75; 95% CI, 1.53-1.99. The OR for use of bisphosphonates and NSAIDs was elevated OR = 2.00; 95% CI, 1.12-3.57. This risk was still elevated for users of bisphosphonates and COX-2 inhibitors [OR = 2.38 (95% CI, 1.26-4.50)]. We found no evidence of an increase in the risk of UGB among current users of bisphosphonates. The risk of combined NSAID and bisphosphonate therapy was increased, but this risk was not higher than the risk for NSAID users alone.

Association between risk factors for injurious falls and new benzodiazepine prescribing in elderly persons

BackgroundBenzodiazepines are frequently prescribed to elderly patients' despite concerns about adverse effects leading to injurious falls. Previous studies have not investigated the extent to which patients with pre-existing risk factors for falls are prescribed benzodiazepines. The objective of this study is to assess if some of the risk factors for falls are associated with new benzodiazepine prescriptions in elderly persons.MethodsUsing provincial administrative databases, elderly Quebec residents were screened in 1989 for benzodiazepine use and non-users were followed for up to 5 years. Logistic regression models were used to evaluate potential predictors of new benzodiazepine use among patient baseline characteristics.ResultsIn the 252,811 elderly patients who had no benzodiazepine prescription during the baseline year (1989), 174,444 (69%) never filled a benzodiazepine prescription and 78,367 (31%) filled at least one benzodiazepine prescription. In the adjusted analysis, several risk factors for falls were associated with statistically significant increases in the risk of receiving a new benzodiazepine prescription including the number of prescribing physicians seen at baseline (OR: 1.12; 95% CI 1.11–1.13), being female (OR: 1.20; 95% CI 1.18–1.22) or a diagnosis of arthritis (OR: 1.11; 95% CI 1.09–1.14), depression (OR: 1.42; 95% CI 1.35–1.49) or alcohol abuse (OR: 1.24; 95% CI 1.05–1.46). The strongest predictor for starting a benzodiazepine was the use of other medications, particularly anti-depressants (OR: 1.85; 95% CI 1.75–1.95).ConclusionPatients with pre-existing conditions that increase the risk of injurious falls are significantly more likely to receive a new prescription for a benzodiazepine. The strength of the association between previous medication use and new benzodiazepine prescriptions highlights an important medication safety issue.

Prevalence of psychotropic drug use in nursing homes for the aged in Quebec and in the French-speaking area of Switzerland

The use of psychotropic drugs is high in institutionalised elderly, which raises the question of its appropriateness. This study aimed to: (1) estimate the use of psychotropics, for each family, in terms of the prevalence and dosage among the elderly in nursing homes in French-speaking Switzerland and Quebec; and (2) assess, for each family of psychotropic drugs and for each care facility, the prevalence of use and departure from average prescription (ratio of observed-to-expected prevalence). An administrative database was used for this cross-sectional analysis. The sample included 8183 Quebec and 7592 Swiss long-term care residents. Three classes of psychotropics (antipsychotics, antidepressants, hypnotics-anxiolytics) were defined as dichotomous variables. Logistic regressions were conducted to identify residents characteristics associated with the use of each psychotropic type and to compute expected prevalence. Swiss residents were slightly older and less dependent than Quebec residents. Use of psychotropic drugs was higher in Swiss than in Quebec residents, on the whole as well as for each family of drug. A total of 78.1% of Swiss residents used at least one drug as compared to 66.9% in Quebec. Ninety percent of residents were given less than 7 defined daily doses per week, irrespective of the drug family. According to Beer's criteria, only 4.9% of prescriptions were inadequate. In Quebec and in Switzerland, the prevalence of antidepressant use was associated with the prevalence of hypnotic-anxiolytic use. No ratios of observed-to-expected reached statistical significance. There was a considerable use of psychotropics in Quebec and Switzerland with, seemingly, no dramatic departure from the average practice. Our data cannot tell if there is a global overuse of psychotropics, but indicated that dosage and medication selection seem adequate. Physicians should critically reassess the necessity of prescribed medications for their patients.

The Influence of Motor Vehicle Legislation on Injury Claim Incidence

Although there have been numerous strategies to prevent motor vehicle collisions and their subsequent injuries, few have been effective in preventing motor vehicle injury claims. In this paper, we examine the role of legislation and compensation system in altering injury claim incidence. The population base for our natural experiment was all Saskatchewan, Manitoba, British Columbia and Quebec residents who submitted personal injury claims to their respective motor vehicle insurance provider from 1990 to 1999. The provinces of Saskatchewan and Manitoba switched from Tort to pure No-Fault insurance on January 1, 1995 and on March 1, 1994 respectively. British Columbia maintained tort insurance and Quebec maintained pure no-fault insurance throughout the entire 10-year period. The conversion from tort insurance to pure no-fault motor vehicle insurance resulted in a five-year 31% (RR = 0.69; 95% CI 0.68-0.70) reduction in total injury claims per 100,000 residents in Saskatchewan and a five-year 43% (RR = 0.57; 95% CI 0.56-0.58) reduction in Manitoba. At the same time, the province of British Columbia retained tort insurance and had a five-year 5% reduction (RR = 0.95; 95% CI 0.94-0.99). Quebec, which retained pure no-fault throughout the entire 10-year period, had less than one third of the injury claims per 100,000 residents than the tort province of British Columbia. The conversion from tort to pure no-fault legislation has a large influence in reducing motor vehicle injury claim incidence in Canada. Legislative system and injury compensation scheme have an observable impact on injury claim incidence and can therefore have significant impact on the health care system.

Longitudinal patterns of new Benzodiazepine use in the elderly.

To characterize longitudinal patterns of Benzodiazepine use in the elderly. Prospective cohort of 78 367 community-dwelling Quebec residents aged 66 years or more who were new Benzodiazepine users, was followed for 5 years, 1989-1994. Data acquired from four population-based, provincial administrative databases were used to create time-dependent measures of change in dosage, switching or adding Benzodiazepines for 11 drugs listed in the provincial formulary. Subject-specific Spearman's rank correlation coefficients between dose and time were used to measure the tendency of increasing dose with consecutive periods of use. Multiple logistic regression and generalized estimating equations (GEE) models evaluated subject characteristics associated with increasing dose. The mean duration of uninterrupted Benzodiazepine use was 75.5 days. The mean daily dose was about half the recommended adult daily dose but 8.6% of subjects exceeded the recommended adult dose. Some of them (28.8%) switched medications at least once and 8.2% filled two or more prescriptions concurrently. For women, older age at date of first prescription was associated with increasing dose over time (odds ratio (OR) for 10 year age increase = 1.23, p < 0.001). Long periods of Benzodiazepine use are frequent among Quebec elderly. The evidence of increasing dose, particularly for older women, and long-duration of use has important implications for clinicians.

Impact of a cost sharing drug insurance plan on drug utilization among individuals receiving social assistance

Background: A cost-sharing drug insurance plan has been implemented among people receiving social assistance who had previously free access to medications. Objective: To assess the impact of this drug plan on the use of three classes of medications: inhaled corticosteroids, neuroleptics and anticonvulsants. Methods: From the computerized drug databases of the Régie de l'assurance maladie du Québec (RAMQ), we selected three random samples of Quebec residents receiving social assistance between August 1992 and June 1997 and aged 64 years or less: 55 890 users of inhaled corticosteroids, 29 461 users of neuroleptics and 44 916 users of anticonvulsants. We also obtained data for individuals privately insured by the Commission de la construction du Québec (control group). Comparison of the monthly consumption of medications before and after the new drug plan was done using time series models. Results: For individuals receiving social assistance and using inhaled corticosteroids, we observed a statistically significant decrease of 37% of the monthly consumption for the 11 months following the new drug plan. For neuroleptics and anticonvulsants, we observed a non significant decrease of 9 and 10%, respectively. No decrease in drug consumption was observed in the control group. Conclusion: Inhaled corticosteroids was the only class of medications that was found to decrease significantly after the implementation of the drug insurance plan.

Amiodarone and the risk of bradyarrhythmia requiring permanent pacemaker in elderly patients with atrial fibrillation and prior myocardial infarction

ObjectivesThe aim of this study was to determine whether the use of amiodarone in patients with atrial fibrillation (AF) increases the risk of bradyarrhythmia requiring a permanent pacemaker. BackgroundReports of severe bradyarrhythmia during amiodarone therapy are infrequent and limited to studies assessing the therapy’s use in the management of patients with ventricular arrhythmias. MethodsA study cohort of 8,770 patients age ≥65 years with a new diagnosis of AF was identified from a provincewide database of Quebec residents with a myocardial infarction (MI) between 1991 and 1999. Using a nested case-control design, 477 cases of bradyarrhythmia requiring a permanent pacemaker were matched (1:4) to 1,908 controls. Multivariable logistic regression was used to estimate the odds ratio (OR) of pacemaker insertion associated with amiodarone use, controlling for baseline risk factors and exposure to sotalol, Class I antiarrhythmic agents, beta-blockers, calcium channel blockers, and digoxin. ResultsAmiodarone use was associated with an increased risk of pacemaker insertion (OR: 2.14, 95% confidence interval [CI]: 1.30 to 3.54). This effect was modified by gender, with a greater risk in women versus men (OR: 3.86, 95% CI: 1.70 to 8.75 vs. OR: 1.52, 95% CI: 0.80 to 2.89). Digoxin was the only other medication associated with an increased risk of pacemaker insertion (OR: 1.78, 95% CI: 1.37 to 2.31). ConclusionsThis study suggests that the use of amiodarone in elderly patients with AF and a previous MI increases the risk of bradyarrhythmia requiring a permanent pacemaker. The finding of an augmented risk of pacemaker insertion in elderly women receiving amiodarone requires further investigation.

The Effect of Physicians' Training on Prescribing β-Blockers for Secondary Prevention of Myocardial Infarction in the Elderly

PURPOSE: The objective was to determine whether the year and medical school of graduation, the medical specialty and the sex of the treating physician was associated with prescribing β-blockers after hospital discharge among survivors of myocardial infarction (MI), after adjusting for patient characteristics. METHODS: We carried out a dynamic retrospective cohort study using data from a longitudinal database that contained information on Quebec residents over the age of 65 years sent home from hospital after MI between 1990 and 1993. The outcome was a β-blocker being dispensed after hospital discharge. Logistic regression was used to estimate the association between training characteristics and β-blocker dispensation and clustering of patients within physicians was accounted for using Generalized Estimating Equations. RESULTS: The cohort consisted of 14,334 MI survivors who were treated by 3209 physicians, yielding a mean of about 4.5 patients per physician [standard deviation (SD) = 8.2]. β-blockers were prescribed to approximately one-third of subjects. After adjusting for patients' demographic characteristics, comorbid medical conditions, and markers of MI severity, physicians who were more likely to prescribe a β-blocker included cardiologists and the most recent graduates (graduating after 1989). Systematic differences were also observed between graduates of different medical schools. CONCLUSIONS: After adjusting for differences between patients', the sex of the physician was largely unrelated to prescribing β-blockers for secondary prevention of MI. However, prescribing differed by training characteristics such as medical specialty and year and medical school of graduation.

Impact of a cost-sharing drug insurance plan on drug utilization among older people.

In August 1996, the Régie de l'assurance-maladie du QuEbec (RAMQ), the government body responsible for medical insurance in the Canadian province of Quebec, introduced a cost-sharing drug insurance plan. Before this plan, individuals age 65 years and older had to pay Canadian (CDN)$2 per prescription, with the remaining cost paid by the RAMQ. With the new plan, beneficiaries may have to pay an amount between CDN$200 and CDN$925 per year, depending on their income. Concerned that this financial constraint imposed on older people might have an impact on the use of medications, we investigated whether the consumption of four classes of medications, antihypertensive agents, anticoagulants, nitrates, and benzodiazepines, was affected by the drug plan implementation. Time series models with pre/post comparison group. Administrative computerized databases of the RAMQ. Random sample of Quebec residents age 65 years and older registered in the provincial drug plan between August 1992 and June 1997: 54,771 users of nitrates, 133,146 users of antihypertensive agents, 45,534 users of anti-coagulants, and 26,165 users of benzodiazepines. We modeled the monthly consumption of the medications under study between August 1992 and June 1996. Monthly drug consumptions predicted from the models were compared with those observed for the 13 months (August 1996 to August 1997) following the implementation of the new drug plan using 95% confidence intervals. The number of prescriptions dispensed served as an indicator for drug consumption. During the study period we observed a nonstatistically significant decrease in number of prescriptions of 5.1% for nitrates, 1.1% for antihypertensive agents, and 0.8% for benzodiazepines, and a nonstatistically significant increase of 1.6% for anticoagulants. Residents of Quebec age 65 years and older were not found to have reduced significantly their consumption of nitrates, antihypertensive agents, anticoagulants, and benzodiazepines during the 13 months that followed the implementation of a cost-sharing drug insurance plan.

Management of new symptoms of dyspepsia in the elderly in Quebec.

To use the Régie de l'assurance-maladie du Québec (RAMQ) database to study the clinical strategies used by Quebec physicians in the management of dyspepsia in the elderly. A 20% random sample of the RAMQ database for Quebec residents aged 65 years and older for the three years from July 1, 1991 to June 30, 1992 was used. Patients were placed in three cohorts according to the following treatment strategies: endoscopy, x-ray examination or drug therapy. Patients in each cohort were then categorized as either nonsteroidal anti-inflammatory drug (NSAID) users or non-NSAID users. The choice of drug treatment used to manage the dyspepsia in each cohort was recorded. Drug treatments were divided into the following six antidyspeptic categories: H2 blockers, omeprazole, sucralphate, misoprostol, prokinetic drugs or no drugs. The number of duodenal, oesophageal and stomach cancers diagnosed in each cohort was also counted. Drug therapy was the most frequently used strategy in all patients, and was used more frequently in NSAID users (87%) than in non-NSAID users (69%). A total of 22% of NSAID users in each group, and 46% of NSAID users in the drug therapy group, underwent investigation. H2 blockers were the most prescribed drug in all three treatment strategies, and omeprazole was the second most prescribed drug in the endoscopy and x-ray cohorts. Overall omeprazole was the least prescribed drug. There was a higher rate of cancer detection in the endoscopy and x-ray cohorts than in the drug therapy group. Previous NSAID use greatly influences the way in which physicians treat patients with dyspepsia.

Les initiatives québécoises dans le domaine de la capitalisation des entreprises: Le point de vue des investisseurs

Starting in 1976, the Quebec provincial government has introduced several programs and organisations with the objective of raising equity capital for companies; the Societes de developpement de l'entreprise quebecoise (SODEQ) were followed by the availability of the 'developing company' category under the QSSP and then by the Fonds de Solidarite ( FTQ). These programs were instigated in an attempt to diminish the 'small business under-capitalisation problem'. To attain this and encourage Quebec residents to invest more in equity securities, the government chose tax incentives. Nevertheless, unlike most tax incentive programs, these were not neutral; by changing the risk-return relationship of securities, the government provoked a redistribution of the savings of Quebec investors. In this study, we evaluate the effect of this redistribution on the wealth of investors and demonstrate that these investments had a very low return, even if the resulting deductions and credits are considered. In fact, the total cost of these programs for investors adds up to $200 millions.

The Language Crisis: An Exchange of Views

This is a brief response to the two articles by Charles Castonguay and Roderic P. Beaujot which appeared in the Winter 197 9 issue. Although readers may be growing weary of linguistic problems and policies, a topic on which this journal has published five articles in less than a year, I hope they will bear with me for one more comment. My reason for asking them to do so arises from the fact that the Castonguay and Beaujot articles are almost identical in viewpoint and my conviction that the alternative point of view deserves to be heard. The essential argument of both Castonguay and Beaujot can be summarized in four propositions, as follows: (1) The French language is weak, and growing weaker in most of Canada. (2) Therefore, most of Canada should be officially English unilingual. (3) The English language is strong, and growing stronger, in Quebec. (4) Therefore, Quebec should be officially French unilingual. Since logic is often alleged to be a French virtue, the fallacy of this argument is presumably apparent to the authors, although they may have hoped it would escape the attention of anglophone readers. Moreover, the factual basis for the argument is just as weak as the logical connections between its parts. It is probably true that the French language outside of Quebec is still in danger, although we will only be able to assess the real effect, if any, of the Trudeau policies when we are in a position to compare the 1981 census data with those of 1971.However, there is no basis at all for the assertion, frequently made by Quebec nationalists, that French is losing ground in Quebec itself. Castonguay actually refers to an 'existing net trend towards anglicisation in Acadia and even in Quebec itself, especially in the core Montreal area.' However, the first of the tables that accompany Beaujot's article suggests a different conclusion. If the numbers of Quebec residents having English, French, and other mother tongues in 1976 are compared with the numbers in 1971, a simple calculation reveals that French mother tongue increased by 4.4 per cent in the five year period prior to the victory of the Parti Quebecois, while English increased by only 3.3 per cent and 'others' actually decreased (for the first time in history) by 8.4 per cent. Since the English group in Quebec augments itself by assimilating immigrants, and not to any significant extent by assimilating francophones, this indicates that the pool of potential anglophones in Quebec is diminishing. In fact the table also reveals that the absolute number of persons with mother tongues other than French diminished slightly in Quebec between 1971 and 1976. It will probably have diminished considerably by 1981. One problem in attempting to conduct a rational dialogue with Quebec nationalists is the fact that almost any assertion about Quebec's anglophone minority can be used as the basis for a nationalist argument. If the anglophone minority is strong, the nationalists argue that this proves the existence of undeserved privileges that should be taken away from it. If the anglophone minority is weak, the nationalists argue that it can be ignored as part of some new accommodation between Quebec and the rest of Canada. Castonguay indeed assures us that a sell-out of the Quebec anglophones (euphemistically described as 'a language policy based on the principle of territorial bilingualism') could 'help to alleviate the basic