Important treatment gaps in vascular protection for the elderly after type 2 diabetes therapy initiation

BACKGROUND

Canadian practice guidelines recommend the use of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) for vascular protection in individuals with diabetes who are at high risk of cardiovascular events, including those ≥ 65 years. We estimated the proportion of elderly persons who initiated an ACEI or an ARB in the year after beginning oral antidiabetes (OAD) treatment, and we identified factors associated with this initiation.

METHODS

Using the Quebec Health Insurance Board (RAMQ) databases, we conducted a population-based cohort study of individuals ≥ 65 years recently prescribed an OAD. We excluded those who were already taking an ACEI or ARB. Factors associated with ACEI or ARB initiation were identified using multivariate logistic regression.

RESULTS

Among 43,700 individuals, 13,621 (31.2%) initiated an ACEI or ARB in the year after beginning OAD. Individuals were more likely to begin an ACEI or an ARB if they initially received both metformin and a sulfonylurea, lived in a rural region, began OAD treatment between 2001 and 2006, were hospitalized, or had ≥ 22 medical visits in the year before OAD initiation. Individuals ≥ 75 years, those who were prescribed an OAD by a general practitioner, initially received a sulfonylurea, or received ≥ 4 different medications in the year before OAD initiation were less likely to begin an ACEI or ARB.

CONCLUSIONS

In the elderly not already taking ACEIs or ARBs, a low proportion of those undertaking OAD treatment are prescribed the recommended cardioprotection of an ACEI or ARB in the following year. Interventions are needed to close this treatment gap.

The adequacy of pharmaceutical treatment of schizophrenia in Quebec varies with age, but is not influenced by sex or neighbourhood deprivation

OBJECTIVE

Though high discontinuation rates for antipsychotics (APs) by patients with schizophrenia are frequently reported, the percentage of patients receiving pharmaceutical treatment for schizophrenia in routine practice in accordance with international clinical guidelines is unknown. Further, it is unknown if these rates are influenced by levels of neighbourhood deprivation or by a patient's age or sex. Our study aims to investigate if inequalities in AP treatment could be observed between patients living in neighbourhoods with the highest levels of material and social deprivation and those with the lowest deprivation levels, between patients from different age groups, or between men and women.

METHODS

We conducted a secondary analysis of medical-administrative data of a cohort of adult patients in the province of Quebec with a medical contact for schizophrenia in a 2-year period (2004-2005). We assessed the proportion of patients that filled at least 1 prescription for an AP and received adequate pharmaceutical treatment, defined as being in possession of APs at least 80% of the time as outpatients during a 2-year follow-up period.

RESULTS

Among the 30 544 study patients, 88.5% filled at least 1 prescription for an AP, and 67.5% of the treated patients received adequate treatment. Though no clinically significant differences were observed by deprivation or sex, younger age was associated with lower proportions of patients receiving adequate treatment (46% of treated patients aged between 18 and 29 years, compared with 72% aged between 30 and 64 years, and 77% aged 65 years and over).

CONCLUSIONS

In Quebec's routine practice, over 70% of treated patients aged 30 and over received adequate pharmacological treatment, regardless of sex or neighbourhood socioeconomic status. In contrast, in patients aged between 18 and 29 years this percentage was 47%. This is a discouraging finding, especially because optimal treatment in the early phase of disease is reported to result in the best long-term outcomes.

Immunization services offered in Québec (Canada) pharmacies

Canadian Pharmacists are easy to reach. Although Québec pharmacists are not allowed to administer vaccines, they can: (1) promote vaccination, (2) counsel patients on vaccination, (3) sell vaccines and (4) provide vaccine administration by a nurse. Our objectives were to describe immunization services given in Québec pharmacies and assess the potential relation between, on one hand, pharmacy characteristics and difficulties perceived by pharmacists and, on the other hand, vaccine administration. In 2008-09, an anonymous questionnaire was mailed to all Québec pharmacy owners (n = 1663). Among the 1102 (66%) respondents, 90% stated that vaccines were sold, 27% that a nurse administered vaccines in their pharmacy and 44% were planning to offer vaccine administration in the next five years. Three out of four stated they were doing vaccine promotion and 65%, vaccine counselling. Half of respondents said they would be willing to administer vaccines themselves if legislative modifications were made. Recommendations for cold chain maintenance were followed in 23% of pharmacies selling vaccines. Presence of another health professional in the pharmacy, higher number of opening hours, not being located in the same building than a medical clinic and having an agreement to collaborate with a public health unit or a medical clinic for immunization were positively associated with vaccine administration in multivariate analysis. Higher perceived difficulties with lack of demand from patients were negatively associated with vaccine administration. Most pharmacists are willing to increase their involvement in immunization. Collaboration between public health professionals and pharmacists should be reinforced.

Spatio-temporal clustering of the incidence of schizophrenia in Quebec, Canada from 2004 to 2007

Exploring spatio-temporal patterns of disease incidence can help to identify areas of significantly elevated or decreased risk, providing potential etiologic clues. In this study, we present a spatio-temporal analysis of the incidence of schizophrenia in Quebec from 2004 to 2007 using administrative databases from the Régie de l'Assurance Maladie du Quebec and the hospital discharge database. We conducted purely spatial analyses for each age group adjusted by sex for the whole period using SatScan (version 9.1.1). Findings from the study indicated variations in the spatial clustering of schizophrenia according to sex and age. In term of incidence rate, there are high differences between urban and rural-remote areas, as well as between the two main metropolitan areas of the province of Quebec (Island of Montreal and Quebec-City).

Hypoglycemia-related emergency department visits and hypoglycemia-related hospitalizations among new users of antidiabetes treatments

OBJECTIVE

To describe the burden of severe hypoglycemia among new users of insulin and oral antidiabetes drugs (OAD) in terms of 2 hypoglycemia-related outcomes: emergency department (ED) visit and hospitalization.

METHODS

We conducted an inception cohort study using the databases of the Quebec health insurance board and the Quebec registry of hospitalizations. The source population was made of individuals 18 years of age or older who were newly dispensed an antidiabetes treatment made of either insulin or OAD between January 1, 2000 and December 31, 2008. Individuals were followed from initiation of antidiabetes treatment to December 31, 2008, occurrence of hypoglycemia-related outcome, loss of eligibility to the drug plan or death, whichever came first. Individuals' characteristics at antidiabetes treatment initiation were described using frequency distributions. The incidence rate for the occurrence of hypoglycemia-related ED visit and hypoglycemia-related hospitalization were calculated using the Kaplan-Meier method.

RESULTS

A total of 188 659 new users of antidiabetes treatment were included in the cohort. A total of 3575 (1.9%) individuals had at least 1 hypoglycemia-related ED visit whereas 194 (0.1%) had at least 1 hypoglycemia-related hospitalization. Incidence rates for the occurrence of hypoglycemia-related ED visits and hypoglycemia-related hospitalizations were 5.2 and 0.3 cases per 1000 patient years, respectively.

CONCLUSION

Although the incidence of ED visit or hospitalization due to hypoglycemia seems low, severe hypoglycemia episodes could be associated with a high economic burden.

The impact of the type of insurance plan on adherence and persistence with antidepressants: a matched cohort study

OBJECTIVE

To compare adherence to, and persistence with, antidepressants (AD) in Quebec patients who are covered by private and public drug insurance.

METHOD

A matched cohort study was conducted using prescription claims databases: reMed, a medication data registry for Quebec residents covered by private drug insurance, and Régie de l'assurance maladie du Québec database for Quebec residents with public drug insurance. Patients were aged 18 to 64 years and filled at least 1 prescription for an AD in monotherapy between December 2007 and September 2009 (194 privately and 2055 publicly insured patients). Adherence over 1 year was estimated using the proportion of prescribed days covered (PPDC). The difference in mean PPDC between patients with private and public drug insurance was estimated with linear regression. Persistence was compared between the groups with a Cox regression model.

RESULTS

The PPDC was 86.4% (95% CI 83.3% to 89.5%) in privately insured and 82.2% (95% CI 78.5% to 85.9%) in publicly insured patients and the adjusted mean difference was 5.1% (95% CI 1.6% to 8.6%). Persistence was 51.0% in the private group and 19.7% in the public group at 1 year (P < 0.001); the adjusted hazard ratio was 0.49 (95% CI 0.30 to 0.79).

CONCLUSION

Better adherence and persistence were observed in privately insured patients. Adherence difference may be due to lower copayment among privately insured patients.

Comparative safety of antipsychotics: another look at the risk of diabetes

OBJECTIVE

The association between the use of antipsychotics and diabetes mellitus (DM) is still unclear, as depicted by several conflicting reports. Our study aims to assess the risk of DM in new users of antipsychotics.

METHODS

Our nested case-control study used the Quebec Health Insurance Board databases. People in the source cohort were DM-free and had initiated an antipsychotic treatment. Subjects were cohort members who initiated an antidiabetic or had a diagnosis of DM during their follow-up period. Three variables were used to assess antipsychotic exposure: the antipsychotic used (any typical, clozapine, olanzapine, quetiapine, risperidone, or more than 1 drug); the number of 30-day periods of use; and antipsychotic use at index date (current or past). A paired multivariate logistic regression model was used to calculate adjusted odds ratios.

RESULTS

Among the 88 467 people included in the cohort, 6109 subjects with DM were identified and were matched to 61 090 control subjects. New users of quetiapine were less likely to develop DM than new users of typical antipsychotics (OR, 0.89; 95% CI 0.81 to 0.99). The risk of DM was not statistically different across the atypical antipsychotics. A longer exposure to any antipsychotic (for each 30-day period, OR 1.009; 95% CI 1.006 to 1.011) and current use of antipsychotics (OR 1.26; 95% CI 1.17 to 1.36) were associated with DM.

CONCLUSION

These results suggest that metabolic parameters of people exposed to antipsychotics should be monitored, irrespective of the drug taken, among the drugs available at the time of analysis.

[Health inequities in mood disorders based on material and social deprivation in dwelling sectors ]

OBJECTIVE

To compare mood disorder (MD) prevalence in Quebec in 2006, and compare health services and medication use, mortality and morbidity in patients with MD based on sex and the dwelling sector level of material and social deprivation. The objective was also to identify subgroups of individuals using health services in a larger proportion and having a higher risk of morbidity and mortality.

METHOD

We conducted a secondary analysis of the Régie de l’assurance maladie du Québec medico-administrative data. The cohort is composed of adults diagnosed with MD and living in Quebec in 2006. Variables include: physician consultation, medication demand, consultation for substance or alcohol abuse, emergency visit, hospitalization for a mental disorder, and death. Dwelling sector types are defined by crossing Pampalon material and social deprivation quintiles.

RESULTS

MD prevalence in 2006 was 3.06% (177 850 patients), with prevalence in women 1.7-fold with respect to men. Findings show a higher MD prevalence as well as a higher mortality and morbidity rate in materially and socially deprived dwelling sectors. Young men also represent a specifically vulnerable subgroup for many study variables.

CONCLUSION

Public policies aimed at improving material conditions (income, education, employment) and breaking out social isolation would have an important impact on the population mental health. Public health program development should pay close attention to young men population.

Treatment prevalence and incidence of schizophrenia in Quebec using a population health services perspective: different algorithms, different estimates

PURPOSE

Using a population health services perspective, this article defines and assesses an efficient criteria-based algorithm to identify treatment prevalent and incident cases of schizophrenia. We refer here "treatment" prevalence and incidence since its evaluation depends on a patient receiving a health care service with a diagnosis of schizophrenia.

METHODS

A population-based cohort study was conducted among all adults having a hospital discharge or a physician claim for schizophrenia in the public health plan databases between January 1996 and December 2006. Four algorithms to characterize patients with schizophrenia were defined. To identify treatment incident cases in 2006, we removed from the treatment prevalent pool patients with a previous record of schizophrenia between 1996 and 2006 (10-year clearance period). Using this 10-year period as reference, Kappa coefficients (KC) and positive predictive values (PPV) were calculated to determine the "optimal" length of clearance period to identify incident cases.

RESULTS

The lifetime treatment prevalence and incidence of schizophrenia varied from 0.59 to 1.46% and from 42 to 94 per 100,000, respectively. When compared to the 10-year clearance period, the KC is excellent in a clearance period of 6-7 years. To achieve a PPV of 90%, a clearance period of 7-8 years would be necessary.

CONCLUSIONS

With an appropriate algorithm, treatment prevalence and incidence of schizophrenia can be conveniently estimated using administrative data. These estimates are a vital step toward appropriate planning of services for schizophrenia.

Persistence patterns with oral antidiabetes drug treatment in newly treated patients--a population-based study

OBJECTIVE

We assessed persistence patterns with oral antidiabetes drug (OAD) in patients newly dispensed with different OAD classes.

METHODS

We conducted a population-based cohort study using Quebec Health Insurance Board data. Patients aged 18 years or more newly dispensed an OAD between January 1, 1998 and December 31, 2003 were included in the study (n=98,940). Persistence was defined as consistently refilling a prescription for the initial OAD within three times the days' supply of the preceding claim. For nonpersistent patients, a second course of therapy was defined as treatment initiation with any OAD after a first discontinuation. Patients were followed from treatment initiation up to December 31, 2004, ineligibility for the drug plan or death, whichever came first, and treatment discontinuation or second course of treatment. Cox regression models were used to compute adjusted hazards ratios (AHR) of persistence and initiation of second courses of therapy.

RESULTS

The probability of persisting with the initial OAD over a 12-month period was 65% and 56% for patients initiated on metformin and sylfonylurea, respectively. Compared to metformin, the likelihood of discontinuing the initial OAD over the study period was significantly higher for patients on sulphonylureas (AHR: 1.32; 95% CI 1.29-1.34). Patients started on sulphonylureas were also less likely to start a second course of therapy after a first treatment discontinuation (AHR: 0.91; 95% CI 0.89-0.93).

CONCLUSIONS

Compared to diabetic patients initiated on metformin, those initiated on sulphonylureas displayed poorer persistence patterns.

Initiation of insulin therapy in elderly patients taking oral antidiabetes drugs

BACKGROUND

We sought to estimate the rate of initiation of insulin therapy among elderly patients using oral anti-diabetes drugs and to identify the factors associated with this initiation.

METHODS

We conducted a population-based cohort study involving people aged 66 or more years who were newly dispensed an oral antidiabetes drug. Individuals who had received acarbose or a thiazolidinedione were excluded. The rate of insulin initiation was calculated by use of the Kaplan-Meier method. Factors associated with insulin initiation were identified by multivariable Cox regression analyses.

RESULTS

In this cohort of 69,674 new users of oral antidiabetes drugs, insulin was initiated at rate of 9.7 cases per 1000 patient-years. Patients who had initially received an insulin secretagogue (rather than metformin), who were prescribed an oral antidiabetes drug by an endocrinologist or an internist, who received higher initial doses of an oral antidiabetes drug, who received oral corticosteroids, used glucometer strips, or were admitted to hospital in the year before initiation of oral antidiabetes therapy, or who received 16 or more medications were more likely than those without these characteristics to have insulin therapy initiated. In contrast, patients who received thiazides or who used up to 12 medications (v. none) were less likely to have insulin therapy initiated.

INTERPRETATION

Several factors related to drugs and health services are associated with the initiation of insulin therapy in elderly patients receiving oral antidiabetes drugs. It is unclear whether these factors predict secondary failure of oral antidiabetes drugs or instead reflect better management of type 2 diabetes.

A population-based cost-effectiveness analysis of olanzapine and risperidone among ambulatory patients with schizophrenia

BACKGROUND

Olanzapine and risperidone are atypical antipsychotics exhibiting different pharmacological properties that are likely to translate into differences in outcomes, tolerability and safety. As well, their acquisition cost differs. These differences may impact their cost-effectiveness.

OBJECTIVE

To estimate the incremental cost-effectiveness ratio (ICER) of olanzapine and risperidone in an outpatient population.

METHODS

We carried out a cost-effectiveness analysis based on resource utilization data gathered from Quebec's provincial health insurance board databases. Patients previously diagnosed with schizophrenia who received a first prescription of olanzapine or risperidone between 1 January 1997 and 31 August 1999 were followed for 365 days. Absence of hospitalization for mental illness served as the clinical indicator of effectiveness. Direct health care costs for mental illness were considered. Adjusted ICERs were calculated, and their 95% confidence intervals (CI) were assessed using a non-parametric bootstrap.

RESULTS

A total of 6,334 patients were included in the analysis. The ICER for olanzapine was (CA$) 86,918 (95%CI, 27,709 to 237,040) per additional effective treatment per year, among patients hospitalized prior to their treatment. Among those who were not hospitalized prior to their treatment, olanzapine was dominated (95%CI, CA$1.7M to dominated).

CONCLUSION

Results suggest that, in this population, direct mental health care costs could be minimized by using risperidone instead of olanzapine as the initial treatment.

Adherence to atypical antipsychotic treatment among newly treated patients: a population-based study in schizophrenia

BACKGROUND

Lack of adherence to drug treatment is a major obstacle to disease control. Although many studies have examined adherence to antipsychotic treatment, they have generally suffered from lack of differentiation between persistence and compliance as 2 separate components of adherence.

OBJECTIVES

In an outpatient population, to (1) measure the proportion of atypical antipsychotic users who were still on antipsychotic treatment after 12 months, (2) measure the proportion of compliant users among them, and (3) identify the determinants of persistence and of compliance.

METHOD

We carried out a population-based cohort study using the Quebec Health Insurance Board database. Patients previously diagnosed with schizophrenia (ICD-9 criteria) and initiated on clozapine, olanzapine, quetiapine, or risperidone treatment between January 1, 1997, and August 31, 1999, were included. Patients still undergoing treatment with any atypical antipsychotic drug 1 year after their first prescription were considered persistent. Of these patients, those with a supply of drugs for at least 80% of the days were deemed compliant. To identify the characteristics associated with both outcomes, we built a multivariate logistic regression model using a stepwise procedure and calculated odds ratios and their 95% confidence interval.

RESULTS

Of 6662 individuals initiated on treatment with atypical antipsychotics, 4495 (67.5%) were still on the treatment after 1 year, and 3534 (78.6% of those who persisted) were compliant. Patients more likely to be both persistent and compliant were those initiated on clozapine, those who received a treatment of medium or high intensity, those who had used atypical antipsychotics, those without a history of substance-use disorder, and those on welfare. On the other hand, patients who were prescribed their first atypical antipsychotic by a psychiatrist were more likely to be persistent, whereas those with a high comorbidity index and those aged 35 years or more were more likely to be compliant.

CONCLUSIONS

One year after treatment initiation, almost a third of patients were no longer treated with atypical antipsychotics. Of those still being treated, more than 20% were noncompliant. Further studies should focus on means of improving such erratic treatment behaviors.

Toll-like receptors, cytokines and the immunotherapeutics of asthma

Asthma is a complex disease caused by a poorly characterized set of genetic and environmental factors whose pathology is a result of immune dysregulation. Toll-like receptors are pathogen associated molecular pattern receptors expressed by many airway and pulmonary tissues as well as cells of the innate and adaptive immune system. Ligation of toll-like receptors can lead to a change in the expression levels of multiple inflammatory and anti-inflammatory mediators which are involved in the pathogenesis of asthma. These ligands and their receptors are therefore prime candidates in the search for immunotherapeutic treatments of asthma. The use of murine models of allergic asthma as tools for the genetic dissection of this disease should allow the molecular mechanisms underlying asthma to be identified and possibly used as further immunotherapeutic targets.

Effects of job strain on blood pressure: a prospective study of male and female white-collar workers

OBJECTIVES

We evaluated whether cumulative exposure to job strain increases blood pressure.

METHODS

A prospective study of 8395 white-collar workers was initiated during 1991 to 1993. At follow-up, 7.5 years later, 84% of the participants were reassessed to estimate cumulative exposure to job strain.

RESULTS

Compared with men who had never been exposed, men with cumulative exposure and those who became exposed during follow-up showed significant systolic blood pressure increments of 1.8 mm Hg (95% confidence interval [CI]=0.1, 3.5) and 1.5 mm Hg (95% CI=0.2, 2.8), respectively, and relative risks of blood pressure increases in the highest quintile group of 1.33 (95% CI = 1.01, 1.76) and 1.40 (95% CI = 1.14, 1.73). Effect magnitudes were smaller among women. Effects tended to be more pronounced among men and women with low levels of social support at work.

CONCLUSIONS

Among these white-collar workers, exposure to cumulative job strain had a modest but significant effect on systolic blood pressure among men. The risk was of comparable magnitude to that observed for age and sedentary behavior. Men and women with low levels of social support at work appeared to be at higher risk for increases in blood pressure.

Predictors of self-reported noncompliance with antihypertensive drug treatment: a prospective cohort study

BACKGROUND

Persistence and compliance are different aspects of the broader concept of adherence to drug treatment. In a prior study, determinants of nonpersistence in a group of patients newly prescribed antihypertensive medications were examined.

OBJECTIVE

To determine noncompliance among those who were persistent with therapy.

METHODS

A prospective cohort study was conducted, in which individuals prescribed a new antihypertensive monotherapy were identified through a network of 173 pharmacies. Participants were interviewed by telephone twice during a three-month period. At the end of this period, individuals who reported still taking the medication initially prescribed were included in the analysis. Self-reported noncompliance was measured at three months. Data were analyzed using a multivariate logistic regression model.

RESULTS

Of 509 eligible participants, 118 (23.2%) reported noncompliance with their drug treatment. Noncompliance was significantly associated with the use of angiotensin-converting enzyme inhibitors (adjusted OR [AOR] 3.0; 95% CI 1.17 to 7.92) compared with the angiotensin II receptor blocker losartan, and with the belief that hypertension is not a risk factor for cardiovascular diseases (AOR 2.0; 95% CI 1.21 to 3.33). On the other hand, noncompliance was inversely associated with the use of more than four pills of medication per day (AOR 0.3; 95% CI 0.15 to 0.64).

CONCLUSIONS

Compliance with drug treatment could be improved by proper selection of medication, and by attempts to correct the false perceptions patients may have about hypertension. Further research is needed to better understand the clinical significance of a higher number of pills as a predictor of good compliance. Further research is also needed using different means of measuring noncompliance.

TLR7 ligand prevents allergen-induced airway hyperresponsiveness and eosinophilia in allergic asthma by a MYD88-dependent and MK2-independent pathway

Asthma is one of the leading causes of childhood hospitalization, and its incidence is on the rise throughout the world. Currently, the standard treatment for asthma is the use of corticosteroids to try to suppress the inflammatory reaction taking place in the bronchial tree. Using a murine model of atopic allergic asthma employing a methacholine-hyperresponsive (A/J) as well as a hyporesponsive (C57BL/6) strain of mice sensitized and challenged with ovalbumin, we show that treatment with a synthetic Toll-like receptor 7 (TLR7) ligand (S-28463, a member of the imidazoquinoline family) prevents development of the asthmatic phenotype. Treatment with S-28463 resulted in a reduction of airway resistance and elastance following ovalbumin sensitization and challenge. This was accompanied by a dramatic reduction in infiltration of leukocytes, especially eosinophils, into the lungs of both C57BL/6 and A/J mice following OVA challenge. Treatment with S-28463 also abolished both the elevation in serum IgE level as well as the induction of IL-4, IL-5, and IL-13 by OVA challenge. The protective effects of S-28463 were also observed in MK2 knockout, but not MYD88 knockout, mice. We did not observe a switch in cytokine profile from TH2 to TH1, as both IL-12p70 and IFN-γ levels were reduced following S-28463 treatment. These results clearly demonstrate the anti-inflammatory effect of imidazoquinolines in an allergic asthma model as well as the clinical potential of TLR7 ligands in the treatment of allergic diseases.

Effect of drug utilization reviews on the quality of in-hospital prescribing: a quasi-experimental study

Background

Drug utilization review (DUR) programs are being conducted in Canadian hospitals with the aim of improving the appropriateness of prescriptions. However, there is little evidence of their effectiveness. The objective of this study was to assess the impact of both a retrospective and a concurrent DUR programs on the quality of in-hospital prescribing.

Methods

We conducted an interrupted time series quasi-experimental study. Using explicit criteria for quality of prescribing, the natural history of cisapride prescription was established retrospectively in three university-affiliated hospitals. A retrospective DUR was implemented in one of the hospitals, a concurrent DUR in another, whereas the third hospital served as a control. An archivist abstracted records of all patients who were prescribed cisapride during the observation period. The effect of DURs relative to the control hospital was determined by comparing estimated regression coefficients from the time series models and by testing the statistical significance using a 2-tailed Student's t test.

Results

The concurrent DUR program significantly improved the appropriateness of prescriptions for the indication for use whereas the retrospective DUR brought about no significant effect on the quality of prescribing.

Conclusion

Results suggest a retrospective DUR approach may not be sufficient to improve the quality of prescribing. However, a concurrent DUR strategy, with direct feedback to prescribers seems effective and should be tested in other settings with other drugs.

Ambulatory use of olanzapine and risperidone: a population-based study on persistence and the use of concomitant therapy in the treatment of schizophrenia

OBJECTIVE

To assess treatment discontinuation and concomitant use of other antipsychotics among individuals initiated on olanzapine or risperidone for the treatment of schizophrenia.

METHOD

Using data from the Quebec health insurance plan and the Quebec database for hospitalization, we conducted a population-based cohort study of patients for whom a first claim for olanzapine or risperidone was submitted between 1 January 1997 and 31 August 1999. Included were 6405 patients with schizophrenia whom we followed from the date of the first claim for olanzapine or risperidone either to discontinuation date, end of eligibility for the drug plan, 365 days, date of moving out of the province, or date of death. We used Cox regression models to compute hazards ratios (HRs) of having the treatment discontinued and logistic regression models to compute odds ratios (ORs) among persisting patients of having any concomitant antipsychotic prescription. All models were adjusted for age, sex, schizophrenia disorder, comorbidity, region, beneficiary type, substance use disorder, and prior hospitalization for mental illness.

RESULTS

Compared with risperidone users (n = 2718), discontinuation rates were lower for olanzapine users (n = 3687; HR = 0.79; 95%CI, 0.74 to 0.84). The odds of receiving any concomitant antipsychotic prescription did not differ statistically between olanzapine and risperidone users (OR 0.85; 95%CI, 0.71 to 1.01).

CONCLUSIONS

The study results suggest that new users of olanzapine were less likely to discontinue their initial treatment than were new users of risperidone, although discontinuation was high in both groups. Among those who persisted, concomitant use of other antipsychotics did not differ between olanzapine users and risperidone users.

[Drug prescription practices in public medical centres in Gabon]

CONTEXT OF THE PROBLEM

Inappropriate drug use constitutes a major problem of health programs in developing countries. The objective of this study was to describe and assess the quality of drug prescription practices in public medical centres in Gabon.

METHOD

Using the Drug Use Prescribing Indicators developed collaboratively by the World Health Organization (WHO) and the International Network for Rational Use of Drugs (INRUD), we retrospectively evaluated the drugs prescribed during 1,200 randomly selected outpatient consultations that took place in 20 randomly selected public medical centres during the period between July 1, 1997 and June 30, 1998.

RESULTS

A total of 3,054 drugs were prescribed during the 1,200 consultations under study, for an average of 2.6 (Standard Deviation: +/- 1.2) drugs per consultation. Of all the drugs prescribed, 13.5% (95% Confidence Interval (CI): 12.3-14.7) were prescribed under their international nonproprietary name (INN), while 57.1% (CI: 55.3-58.9) appeared on the national list of essential drugs. 64.5% (CI: 61.8-67.2) consultations resulted in the prescription of an antibiotic, while 21.8 % (CI: 19.5-24.1) led to the prescription of at least one injection. On average, six key drugs out of eleven were available in the medical centres visited.

CONCLUSION

The results of this study suggest that drug prescriptions are far from optimal in the public medical centers in Gabon. Among other things, the prescription of drugs under their INN is very low. These findings highlight the need to develop and implement programs that seek to improve the quality of drug prescriptions in Gabon.

Measures of adherence based on self-report exhibited poor agreement with those based on pharmacy records

OBJECTIVE

To assess the level of agreement between a self-reported measure of adherence with prescribed drug and a measure of adherence based on pharmacy data.

METHODS

During an in-home interview, people aged 65+ were asked to report all prescription drugs they had taken in the preceding month. For each drug, a four-item questionnaire was used to determine self-reported adherence. In the pharmacy records, each drug that had been filled at least four times was analyzed, and the percentage of days with the drug available was calculated. Two types of adherence were studied: (1) adherence by individual, and (2) adherence by drug. The level of agreement was assessed using kappa (kappa) statistics and proportions of agreement.

RESULTS

We compared the adherence measures among 189 individuals (880 drugs). Among all, 90 individuals (48%) self-reported adherence, whereas 95 individuals (50%) were adherent according to the records. The level of agreement between these two measures was slight (kappa=0.16 [95% CI: 0.02-0.30]). Individuals self-reported to be adherent for 81% of the drugs, while pharmacy records showed adherence for 83% of them (kappa=0.13 [95% CI: 0.05-0.20]).

CONCLUSION

Self-reported measures of adherence exhibited poor agreement with those based on pharmacy records.

Health-related quality of life in hypertension: impact of a pharmacy intervention programme

BACKGROUND AND OBJECTIVE

In a previous study, we observed that a pharmacy-based intervention programme decreased the blood pressure of hypertensive patients. The objective of the present study was to assess the effect of this pharmacy programme on the health-related quality of life (HRQOL) of individuals treated for hypertension.

METHODS

In a quasi-experimental cohort pilot study, we recruited 91 participants from nine pharmacies in the Quebec City area. We offered the intervention programme over a 9-month period to participants enrolled at four of the pharmacies. The other participants were not exposed to pharmaceutical services other than those usually given by their pharmacists. We used the SF-36 to evaluate HRQOL. Covariance analysis was used to test for significant differences of HRQOL scores between participants exposed and not exposed to the programme.

RESULTS AND DISCUSSION

When compared with the non-exposed participants, those receiving the intervention and with high income had an improvement in vitality score (P=0.05). On the contrary, low-income exposed participants did not show this benefit and had a decline in mental health score (P=0.01). Improvement in vitality is likely due to increased physical activity and to a reduction in systolic blood pressure in the high-income exposed group. The negative effect of the programme on the mental health of those exposed in the low-income group might be due to the fact that the programme was not effective in reducing blood pressure and may therefore have caused anxiety.

CONCLUSION

Pharmacists' interventions can have both a positive and negative impact on the HRQOL of individuals, treated with antihypertensive agents, depending on income level.

Exploring the risk of diabetes mellitus and dyslipidemia among ambulatory users of atypical antipsychotics: a population-based comparison of risperidone and olanzapine

PURPOSE

To compare the incidence rates of diabetes mellitus and dyslipidemia in ambulatory first-time users of risperidone and olanzapine.

METHODS

The database for the Prescription Drug Insurance Plan in the province of Quebec was used as the data source for a population-based cohort study. Denominalized data were extracted for all ambulatory patients who first received an atypical antipsychotic between 1 January 1997 and 31 August 1999. Eligible patients were categorized as taking: no antidiabetic medication; no lipid reducing medication; neither type of medication. Those who started to use an outcome drug (an antidiabetic or lipid-lowering medication) before the end of the follow-up period (31 August 2000) were considered to have developed the corresponding outcome disease. Incidence rate ratios (IRR) (and 95% confidence intervals) for initiating antihyperglycemic or lipid-lowering drug treatment, or both were calculated. Outcomes on risperidone were compared to those on olanzapine.

RESULTS

A total of 19 582 eligible patients were included in the analysis. Relative to risperidone, olanzapine was associated with a higher risk of initiating a pharmacologic treatment for diabetes [IRR: 1.33 (1.03-1.74)], dyslipidemia [IRR: 1.49 (1.22-1.83)], or either condition [1.47 (1.23-1.76)].

CONCLUSIONS

Olanzapine seems to be associated with a higher risk of developing diabetes and/or dyslipidemia than risperidone. Further prospective studies are needed to rigorously assess the safety of olanzapine.

Insomnia, depression and anxiety disorders and their association with benzodiazepine drug use among the community-dwelling elderly: implications for mental health nursing

Benzodiazepine (BZD) drug use among seniors is an important public health issue because the benefit from their use is moderate and of short duration and numerous adverse events have been linked to their use. Furthermore, there is a significant discrepancy between the prevalence of mental health disorders and BZD drug use in the elderly population, which can be attributed to a measurement issue. The goal of this cross-sectional descriptive study was to determine the prevalence of mental health disorders among seniors using BZD and living in the community, basing this information on both a thorough face-to-face interview and a pair of self-reported validated instruments. Among the 216 seniors recruited in our study, nearly 20 % were users of BZD and over three quarters of them had been using this drug for more than a year. Thirteen subjects were recognized as depressed according to a self-report measure compared to 18 according to the interview. Likewise, 13 seniors were categorized as anxious, based on a self-report questionnaire compared to 39 based on the interview. Among self-reported measures of mental health variables, logistic regression indicated that insomnia increases by 7 the likelihood of using BZD (odds ratio: 7.2) and is the only statistically significant variable associated with BZD consumption. Based on thorough interviews, logistic regression showed that insomnia (odds ratio: 6.9) is still the dominant symptom associated with BZD drugs. In conclusion, our results clearly support the assertion that mental health status is influenced according to how it is measured. Finally, nurses should be aware that not all individuals are capable of expressing their mental health problems using either psychological or emotional terminologies. They may opt for expressing their psychological suffering as a physical symptom such as sleeping problems.

Potentially inappropriate prescriptions for older patients in long-term care

Background

Inappropriate medication use is a major healthcare issue for the elderly population. This study explored the prevalence of potentially inappropriate prescriptions (PIPs) in long-term care in metropolitan Quebec.

Methods

A cross sectional chart review of 2,633 long-term care older patients of the Quebec City area was performed. An explicit criteria list for PIPs was developed based on the literature and validated by a modified Delphi method. Medication orders were reviewed to describe prescribing patterns and to determine the prevalence of PIPs. A multivariate analysis was performed to identify predictors of PIPs.

Results

Almost all residents (94.0%) were receiving one or more prescribed medication; on average patients had 4.8 prescribed medications. A majority (54.7%) of treated patients had a potentially inappropriate prescription (PIP). Most common PIPs were drug interactions (33.9% of treated patients), followed by potentially inappropriate duration (23.6%), potentially inappropriate medication (14.7%) and potentially inappropriate dosage (9.6%). PIPs were most frequent for medications of the central nervous system (10.8% of prescribed medication). The likelihood of PIP increased significantly as the number of drugs prescribed increased (odds ratio [OR]: 1.38, 95% confidence interval [CI]: 1.33 – 1.43) and with the length of stay (OR: 1.78, CI: 1.43 – 2.20). On the other hand, the risk of receiving a PIP decreased with age.

Conclusion

Potentially inappropriate prescribing is a serious problem in the highly medicated long-term care population in metropolitan Quebec. Use of explicit criteria lists may help identify the most critical issues and prioritize interventions to improve quality of care and patient safety.

What Do Québec Children Eat During Their First Six Months?

Study objectives were to describe the introduction of foods and beverages and the use of vitamin and/or mineral supplements among infants aged six months, and to identify factors associated with following Québec recommendations on introducing foods and beverages. Study subjects were primiparous women interviewed by phone when their infants were approximately six months old. Data were gathered on foods and beverages offered to infants, the age at which these were introduced, and supplements. The use of each food, beverage, and supplement was evaluated according to recommendations. Mean age at which foods were introduced and proportions of women who followed recommendations were calculated. Multivariate logistic regression models were used to identify the factors associated with following recommendations. Results indicated that among the 1,937 interviewed mothers, 212 (10.9%) exclusively breast-fed their infants before age four months, 1,073 (55.4%) breast-fed their infants at birth but gave them formula or foods before age four months, and 652 (33.7%) formula-fed their infants at birth. Factors associated with adherence to recommendations were breast-feeding exclusively, being older than 30 years, an annual family income of at least $60,000, and being a non-smoker. Few mothers followed all the recommendations.

Quality of life in hypertension: the SF-12 compared to the SF-36

BACKGROUND

The SF-36 has frequently been used to measure health related quality of life (HRQOL) in hypertension. Recently, the SF-12, a shorter form of the SF-36, has been proposed. However, the validity of the SF-12 in hypertension has not yet been assessed.

OBJECTIVES

To determine the extent to which the SF-12 provides similar measurements of HRQOL to those of the SF-36 in hypertensive individuals.

METHODS

A study assessing the impact of a pharmacy-based intervention program on hypertensive individuals served as background for this study. One hundred and twelve individuals participated in this study. We compared the SF-36 with the SF-12 on item scores and summary measures using intraclass correlation coefficients (ICC), Pearson correlation coefficients and linear regression.

RESULTS

The concordance between the SF-12 and the SF-36 on both physical (ICC=0.88) and mental (ICC=0.92) component summary scores (PCS and MCS respectively) is high and the relationship is linear and positive. Most of the variance in the SF-36 PCS (R2=0.78) and MCS (R2=0.85) can be explained by their SF-12 counterparts. The SF-12 PCS and MCS are the only significant predictor variables for the corresponding measure of the SF-36.

CONCLUSIONS

The SF-12 appears to be a valid alternative to the SF-36 for clinical practice or research purposes when studying hypertensive individuals and their treatment.

Pharmacist intervention program for control of hypertension

BACKGROUND

Pharmaceutical care programs have been shown to improve outcomes in hypertension. However, most programs required direct access to patient medical chart and patient consultation sessions by appointment.

OBJECTIVE

To follow the current practice of community pharmacy, exploring the effect of an intervention program on blood pressure (BP) and factors affecting BP.

METHODS

Treated hypertensive patients were enrolled in a 9-month controlled study involving 9 community pharmacies. The PRECEDE-PROCEED model was used as conceptual framework to identify factors affecting BP, to incorporate those factors in an intervention program, and to evaluate the impact of the program. A computerized decision-aid tool was used by pharmacists from 4 pharmacies to provide pharmaceutical care to subjects (n = 41); pharmacists from the 5 other pharmacies performed usual care (n = 59). As there was a statistically significant interaction due to family income in describing the impact of pharmacists' intervention on BP, population was stratified by family income in the analyses.

RESULTS

Compared with the control group, the pharmacy program resulted in significant systolic BP reduction (-7.8 vs. 0.5 mm Hg; p = 0.01) and an increase in the proportion of controlled patients only for those with high incomes. In the high-income group, the program also had a positive impact on physical activity, self-reported adherence, health concerns, and information transmitted. The low-income group did not appear to benefit from the program.

CONCLUSIONS

Pharmacist intervention can modify factors affecting adherence, improve adherence, and reduce BP levels in patients treated with antihypertensive agents. Impact of pharmacist intervention on BP differed according to patient income status.

A pharmacy-based health promotion programme in hypertension: cost-benefit analysis

OBJECTIVE

To weigh the costs and benefits of a pharmacy-based health promotion programme implemented in four pharmacies of the Quebec City area, Canada. This programme was developed to improve blood pressure control through activities aimed at improving the quality of prescribing and the adherence to treatment.

DESIGN

Nine pharmacies in Quebec City were included, of which four pharmacies were assigned to the implementation of the health promotion programme. Each time a study participant came to one of these pharmacies to refill his/her antihypertensive medication, the pharmacist would measure and record the participant's blood pressure and assess adherence to drug treatment. The other five pharmacies delivered usual care. The duration of the intervention programme was 9 months. Costs included direct, indirect, and fixed costs, and the costs of pharmacist intervention. Benefits were measured using cost savings induced by pharmacist intervention. Willingness to pay was also considered. A bootstrap method was used to test the between-group difference.

PERSPECTIVE

The study was performed from a societal perspective.

STUDY PARTICIPANTS

100 individuals aged between 34 and 80 years residing in the Quebec City area and taking antihypertensive medication.

MAIN OUTCOME MEASURES AND RESULTS

Participants exposed to the programme had a significant decrease in mean direct costs and a significant increase in mean indirect costs compared with non-exposed participants. Pharmacist interventions involved a mean cost of 30.68 Canadian dollars ($ Can) per participant exposed to the programme. On average, exposed participants were willing to pay $ Can 0.54 per month after the intervention period. Benefits were about ten times higher than costs (1998 values).

CONCLUSIONS

The implementation of this intervention programme seems promising in the quest to improve blood pressure control in terms of both costs and benefits.

Determinants of discontinuation of new courses of antihypertensive medications

Discontinuation of medication use constitutes a major barrier to adequate control of high blood pressure. We examined the effect of an array of potential predisposing, enabling and reinforcing factors on the discontinuation of newly prescribed antihypertensive medications. We conducted a prospective cohort study through a network of 173 pharmacies across Canada where were identified individuals newly prescribed an antihypertensive monotherapy. We interviewed participants by telephone four times to obtain information for a minimum duration of 18 months after entry into the cohort. We analyzed data using a multivariate proportional hazard model. Of 682 eligible participants, 43.3% had discontinued their initial medication at the end of the observation period. Individuals more likely to discontinue their initial medication were those who perceived side effects from this medication [Hazard Ratio (HR) = 1.91; 95% Confidence Interval (CI) 1.47-2.47). Individuals with medication insurance coverage were less likely to discontinue (HR = 0.74; 95% CI 0.55-0.99). Persistence with newly prescribed medications could be improved by selecting antihypertensive medications containing fewer side effects and by lifting economic barriers to drug treatment.

Non-compliance with drug treatment and reading difficulties with regard to prescription labelling among seniors

BACKGROUND; The link between experiencing difficulties in reading or understanding and non-compliance with drug treatment among seniors is not clearly established.

OBJECTIVES

We measured the effect of both difficulties in reading, as well as difficulties in understanding prescription labelling, on non-compliance with drug treatments among seniors. Since the use of a pill organizer prepared by a pharmacist may compensate for the problems in reading, we also checked the potential modifying effect of the use of a pill organizer on these two associations.

METHOD

Data on non-compliance with drug treatment, comprehension of prescription labelling and on the factors potentially linked to non-compliance, were collected during face-to-face interviews with 325 seniors.

RESULTS

In all, 126 respondents (38.8%) were not able to read all the prescription labels and 218 (67.1%) did not fully understand all the information. 153 respondents were non-compliant with their drug treatment. After adjusting for sex, age, living alone or not, having had help with taking the medication, use of a pill organizer, having had sufficient funds to procure his medicine during the previous month, belief in the efficacy of his medication, perception of his state of health, satisfaction with physician-given and pharmacist-given information, as well as the complexity of the treatment, the two associations remained statistically non-significant. The use of a pill organizer was not a modifying factor.

CONCLUSION

Our results did not demonstrate the existence, among seniors, of an association between non-compliance and difficulty in reading and understanding prescription labelling.

Clearance of infection with Mycobacterium bovis BCG in mice is enhanced by treatment with S28463 (R-848), and its efficiency depends on expression of wild-type Nramp1 (resistance allele)

The mouse bcg host resistance gene is known to control the activation of host macrophages for killing of intracellular parasites like Leishmania donovani as well as intracellular bacteria, including Mycobacterium bovis BCG and Salmonella enterica serovar Typhimurium. The Nramp1 gene has been mapped to this locus and affects the efficiency of macrophage activation. It has been shown that imidazoquinoline compounds, including S28463, are able to improve the clearance of a number of intracellular pathogens such as herpes simplex virus 2, human papillomavirus, and Leishmania. The goal of this study was to determine whether S28463 is efficient against infection with another intracellular pathogen, M. bovis BCG, and to determine the molecular basis underlying this effect. To achieve this, B10A.Nramp1(r) and B10A.Nramp1(-/-) mice were infected with M. bovis BCG and treated with S28463. The bacterial content in the spleen from these mice was assayed by a colony-forming assay. In addition, in vitro experiments were performed using bone marrow-derived macrophage cell lines from these mice. These cells were treated with S28463 and/or gamma interferon (IFN-gamma), and nitric oxide (NO) production was measured. Our study was able to show that S28463 acts in synergy with IFN-gamma to increase the production of NO in vitro. We were also able to demonstrate that mice that carried the resistant allele of the Nramp1 gene and were infected with M. bovis BCG responded to treatment with S28463, resulting in a decreased bacterial load after 2 weeks of treatment. Mice that do not express the Nramp1 gene responded only to a very large dose of S28463, and the response was not as efficient as that observed in mice carrying a wild-type Nramp1 allele. Our data provide evidence for the potential of S28463 as an immunomodulator that may be helpful in designing efficient strategies to improve host defense against mycobacterial infection.

Inter-provincial variation in government drug formularies

In Canada, coverage for ambulatory prescription drug expenditures is provided to some groups by provincial drug plans through a provincial formulary. Little is known about the drugs provincial formularies give access to. We report the variation in availability of new drug molecules (NDM) across provincial formularies. We identified 108 NDM approved in Canada between 1991 and 1998. From each drug plan bulletin or formulary, we abstracted names of NDM listed as per 15 January 1999. We compared the level of listing across provinces using kappa coefficients. In the Quebec, BC, Manitoba and Saskatchewan formularies, more than 70% of the NDM were listed. In four provinces, this proportion was lower than 50%. In general, the agreement between formularies was poor. There is a wide variation across provinces in terms of NDM listed in the formularies. This variation reflects inter-provincial differences in the way drugs are selected for coverage.

Tolerability of antihypertensive drugs in a community-based setting

BACKGROUND

Outside the experimental environment of clinical trials, the tolerability of angiotensin-converting enzyme inhibitors (ACEIs), calcium channel blockers (CCBs), and the angiotensin II antagonist losartan has not been compared.

OBJECTIVES

The purpose of this study was to estimate, in current clinical practice, the 3-month cumulative incidence of side effects among first-time users of losartan, ACEIs, and CCBs for hypertension.

METHODS

We conducted a prospective cohort study through a network of 173 pharmacies across Canada to identify patients with hypertension who were newly prescribed monotherapy with losartan, an ACEI, or a CCB. Individuals were interviewed by telephone 3 times over a 3-month period to determine perceived side effects of the antihypertensive medication prescribed. Data were analyzed using a multivariate logistic regression model.

RESULTS

Among the 663 eligible individuals, the 3-month cumulative incidence of perceived side effects was 52.5% (42/80), 60.2% (222/369), and 69.6% (149/214) for those treated with losartan, an ACEI, and a CCB, respectively. After adjustment for sex, age, level of education, number of symptoms perceived the week before entering the study, prior use of antihypertensive drugs, current use of any other drug, drug insurance coverage, and duration of hypertension, the odds of reporting a side effect were significantly higher among patients treated with an ACEI (odds ratio [OR] = 1.78: 95% CI, 1.02-3.12) or a CCB (OR = 2.65; 95% CI, 1.47-4.78) compared with patients treated with losartan.

CONCLUSIONS

In a community-based setting, we observed that losartan is better tolerated than ACEIs and CCBs. Given that the occurrence of side effects may contribute to lower adherence to drug treatment, the low incidence of side effects associated with losartan makes it an attractive antihypertensive drug choice.

Health-related quality-of-life measurement in hypertension. A review of randomised controlled drug trials

In hypertension, tolerability of drug treatment is important because individuals may see the use of antihypertensive medications as more troubling than their seemingly symptomless disease. This may result in noncompliance and ineffectual long term treatment. In the past 15 years, new antihypertensive medications have been marketed on the basis of the advantages they offer with regard to adverse effects and the unavoidable impact of such adverse effects on a person's quality of life. When related to health, quality of life refers to the physical, psychological and social dimensions of health that are influenced by a person's experiences, beliefs, expectations and perceptions. To measure this concept, many instruments, either generic or specific, may be used. The purpose of this study is to describe, by way of a critical review of the literature, the instruments that are most often used in the measurement of health-related quality of life (HR-QOL) in people using antihypertensive drug treatments. We carried out a search of the literature published in English in the period January 1966 to July 2000, looking for randomised controlled trials of antihypertensive drugs. Using the Medline database, we included 77 papers in our review. Our main finding suggests that HR-QOL changes associated with antihypertensive treatment are measured with many different instruments. In almost all studies, at least 1 instrument specific to a health dimension was used, whereas not many used a generic instrument only. The most commonly measured HR-QOL dimensions were cognitive function, symptomatic well-being, sexual function, psychological well-being, sleep dysfunction, social participation and general health perception. Since the choice of dimensions to measure depends not only on the disease but also on the drug, this review adds further evidence that a generic instrument as well as a preference measurement should be added to a specific instrument.

[International Prostate Symptom Scale. Evaluation of the usefulness of a French version]

OBJECTIVE

To evaluate the usefulness of a French-language version of the International Prostate Symptom Scale (I-PSS) by measuring, on this scale and on the quality of life index, the scores of patients with benign prostatic hyperplasia before and after prostate surgery.

METHOD

The questionnaire was completed by 14 men, mostly between 60 and 80 years old, 24 hours before surgery and 1 month and 3 months after surgery.

RESULTS

The French-language scale worked well. Scores changed from 19.1 before surgery to 7.5 3 months after surgery for prostate symptoms and from 8.5 to 4.5 for quality of life.

CONCLUSION

This version of the questionnaire is a valid tool for evaluating prostate symptoms reported by French-speaking people.

Appropriateness of omeprazole prescribing in Quebec's senior population

BACKGROUND

Prescribing omeprazole for the treatment of digestive disorders accounts for an important part of the costs in Quebec's drug benefit plan. In July 1993, the Quebec drug program listed omeprazole, with restriction, in its formulary. On January 1, 1994, this restriction was lifted; since then, omeprazole has been listed in the regular provincial formulary.

OBJECTIVE

To describe the appropriateness of initial omeprazole prescribing in the ambulatory senior population of Quebec in the 27 months after being listed without restriction.

SUBJECTS AND METHODS

A retrospective population-based cohort study was performed using prescription and medical services claims databases of the Quebec drug program. Data were extracted for elderly patients who received their first omeprazole prescription between July 1, 1994 and March 31, 1996.

RESULTS

Among the 47,140 first-time users of omeprazole identified, 7516 (15.9%) had had an endoscopy in the previous six months, 2308 (4.9%) were given an antimicrobial agent and omeprazole simultaneously, and 22,730 (48.2%) received omeprazole after prior use of an H2 receptor antagonist (H2RA) or a prokinetic drug. A total of 26,525 (56.3%) first-time users were prescribed omeprazole based on at least one of the three criteria listed above. Among these users, 729 (2.8%) received an H2RA concurrently with omeprazole. Altogether, 25,796 (54.7%) first-time users received omeprazole appropriately.

CONCLUSIONS

Although reimbursement for omeprazole prescriptions has not been restricted in Quebec since January 1, 1994, it was prescribed appropriately for elderly patients in the majority of cases studied.