Lucie Blais

Drug injection among street youths in montreal: Predictors of initiation

In North America, street youths are generally considered at very high risk of injection drug use. To estimate the incidence rate of injection drug use in this population and to identify predictors of injection drug use, we conducted the present analysis. Among participants to a cohort study initiated in January 1995, we selected subjects who had never injected at study entry and had completed at least one follow-up questionnaire. Predictors of initiation were identified using Cox proportional bazard regression models. Among the 415 never injectors (mean age at entry 19.5 years), 74 had initiated injection by January 2000 (incidence rate 8.2 per 100 person-years). Independent predictors of initiation were recent episode of homelessness; age younger than 18 years; being tattooed; recently using hallucinogens, beroin, and cocainelcrack/freebase; having a friend who injects drugs; and having ever experienced extrafamilial sexual abuse. This study showed that injection drug use is frequent among street youths, but prevention appears possible.

Patterns of increasing beta-agonist use and the risk of fatal or near-fatal asthma.

The association between the use of inhaled beta-agonists by metered-dose inhaler and the risk of fatal or near-fatal asthma has been demonstrated. It shows that asthmatics who use one canister of beta-agonist per month more than the number used by other similar asthmatics have twice the risk of fatal or near-fatal asthma. The present investigation assesses the magnitude of this excess risk when an asthmatic increases his/her own monthly use of inhaled beta-agonists over time. From a previous nested case-control study of 129 deaths and near-deaths from asthma (cases) and 655 controls from a cohort of 12,301 asthmatics, the subset using at least 12 inhalers during the 12 month study period was identified (97 cases and 258 controls). A profile score, ranging 0-11, was formed to quantify the patterns of beta-agonist use over time for each subject, covering the entire spectrum extending from decreasing to increasing use. The relative risk was 15.2 (95% confidence interval (CI) 2.4-96.2) per unit increase of the profile score in subjects with a pattern of increasing beta-agonist use (profile score of 6.5 or more), but this relative risk was only 1.5 (95% CI 0.8-2.6) per unit when the profile score was less than 6.5 (non-increasing use). This relative risk was independent of the risk associated with the total quantity of beta-agonist use in the 12 month period, which remained around 1.6 (95% CI 1.3-2.0) per inhaler per month.(ABSTRACT TRUNCATED AT 250 WORDS)

First treatment with inhaled corticosteroids and the prevention of admissions to hospital for asthma

BACKGROUND Early treatment with inhaled corticosteroids appears to improve clinical symptoms in asthma. Whether a first treatment initiated in the year following the recognition of asthma can prevent major outcomes such as admission to hospital has yet to be studied. METHODS A case-control study nested within a cohort of 13 563 newly treated asthmatic subjects selected from the databases of Saskatchewan Health (1977–1993) was undertaken to investigate the effectiveness of a first treatment with inhaled corticosteroids in preventing admissions to hospital for asthma. Study subjects were aged between five and 44 years at cohort entry. First time users of inhaled corticosteroids were compared with first time users of theophylline for a maximum of 12 months of treatment. The two treatments under study were further classified into initial and subsequent therapy to minimise selection bias and confounding by indication. Odds ratios associated with hospital admissions for asthma were estimated using conditional logistic regression. Markers of asthma severity, as well as age and sex, were considered as potential confounders. RESULTS Three hundred and three patients admitted to hospital with asthma were identified and 2636 matched controls were selected. Subjects initially treated with regular inhaled corticosteroids were 40% less likely to be admitted to hospital for asthma than regular users of theophylline (odds ratio 0.6; 95% CI 0.4 to 1.0). The odds ratio decreased to 0.2 (95% CI 0.1 to 0.5) when inhaled corticosteroids and theophylline were given subsequently. CONCLUSION The first regular treatment with inhaled corticosteroids initiated in the year following the recognition of asthma can reduce the risk of admission to hospital for asthma by up to 80% compared with regular treatment with theophylline. This is probably due, at least in part, to reducing the likelihood of a worsening in the severity of asthma.

Use of inhaled corticosteroids during pregnancy and risk of pregnancy induced hypertension: nested case-control study

Abstract Objective To determine whether the use of inhaled corticosteroids during pregnancy increases the risk of pregnancy induced hypertension and pre-eclampsia among asthmatic women. Design Nested case-control study. Setting Three administrative health databases from Quebec: RAMQ, MED-ECHO, and Fichier des événements démographiques. Participants 3505 women with asthma, totalling 4593 pregnancies, between 1990 and 2000. Main outcome measuresPregnancy induced hypertension and pre-eclampsia. Results 302 cases of pregnancy induced hypertension and 165 cases of pre-eclampsia were identified. Use of inhaled corticosteroids from conception until date of outcome was not associated with an increased risk of pregnancy induced hypertension (adjusted odds ratio 1.02, 95% confidence interval 0.77 to 1.34) or pre-eclampsia (1.06, 0.74 to 1.53). No significant dose-response relation was observed between inhaled corticosteroids and pregnancy induced hypertension or pre-eclampsia. Oral corticosteroids were significantly associated with the risk of pregnancy induced hypertension (adjusted odds ratio 1.57, 1.02 to 2.41), and a trend was seen for pre-eclampsia (1.72, 0.98 to 3.02). Conclusion No significant increase of the risk of pregnancy induced hypertension or pre-eclampsia was detected among users of inhaled corticosteroids during pregnancy, while markers of uncontrolled and severe asthma were found to significantly increase the risks of pregnancy induced hypertension and pre—eclampsia.

Asthma exacerbations during the first trimester of pregnancy and the risk of congenital malformations among asthmatic women

BACKGROUND Uncontrolled maternal asthma during pregnancy has been hypothesized as a cause of congenital malformation, but literature is scare on this topic. OBJECTIVE The aim of this study was to investigate whether asthmatic women who had an exacerbation during the first trimester of pregnancy were more at risk of having a baby with a congenital malformation. METHODS From the linkage of 3 Canadian administrative databases, we reconstructed a cohort of 4344 pregnancies of asthmatic women. Asthma exacerbations were assessed during the first trimester of pregnancy and were defined as a filled prescription for oral corticosteroids, an emergency department visit, or a hospitalization for asthma. Congenital malformations were assessed at birth and during the first year of life of the newborn by using diagnoses recorded in the databases. Generalized estimating equation models were used to estimate adjusted odds ratios of congenital malformations in association with asthma exacerbations. RESULTS In the cohort we identified 398 (9.2%) babies with at least 1 malformation and 261 (6.0%) with a major malformation. The crude prevalences of malformations were 12.8% and 8.9%, respectively, for women who had and those who did not have an exacerbation. The adjusted odds ratio for all malformations was 1.48 (95% CI, 1.04-2.09) when comparing women who had and those who did not have an exacerbation. The corresponding figures were 1.32 (95% CI, 0.86-2.04) for major malformations. CONCLUSION Asthma exacerbations during the first trimester of pregnancy were found to significantly increase the risk of a congenital malformation.

Prevalence and predictors of antidepressant use in a cohort of pregnant women.

Objective  (1) To determine the prevalence of antidepressant utilisation before, during, and after pregnancy, (2) to determine switches, dosages, and classes of antidepressant used during pregnancy, and (3) to identify factors associated with their use at the beginning and at the end of pregnancy.

High doses of inhaled corticosteroids during the first trimester of pregnancy and congenital malformations

BACKGROUND Although reassuring data exist on the use of low-to-moderate doses of inhaled corticosteroids (ICSs) during pregnancy, there are inadequate data for women receiving high doses. OBJECTIVE To investigate the association between doses of ICS during the first trimester of pregnancy and the risk of congenital malformations among women with asthma. METHODS We conducted a cohort study of 13,280 pregnancies of women with asthma (1990-2002) by linking 3 administrative databases from Quebec (Canada). By using generalized estimation equation models, we compared women taking >0 to 1000 microg/d ICS (beclomethasone dipropionate-chlorofluorocarbone equivalent) with women taking >1000 microg/d and those not taking ICSs. The main outcome measures were all and major congenital malformations. RESULTS We identified 1257 infants with a congenital malformation (9.5%) and 782 infants with a major malformation (5.9%). We found that women who used >1000 microg/d ICS (n = 154) were significantly more likely (63%) to have a baby with a malformation than the 4392 women who used >0 to 1000 microg/d (adjusted risk ratio, 1.63; 95% CI, 1.02-2.60). On the other hand, women who used >0 to 1000 microg/d were not found to be more at risk than women who did not use ICSs during the first trimester (n = 8734). Nonsignificant trends of similar magnitude were found for major malformations. CONCLUSIONS Our study adds evidence on the safety of low-to-moderate doses of ICS taken during the first trimester but raises concerns about high doses. However, we cannot rule out the possibility of residual confounding by severity in this association.

Use of inhaled corticosteroids during the first trimester of pregnancy and the risk of congenital malformations among women with asthma

Aim: To investigate whether the maternal use of different doses of inhaled corticosteroids (ICSs) during the first trimester of pregnancy for the treatment of asthma increases the risk of congenital malformations in the offspring. Methods: From the linkage of three administrative Canadian databases, a cohort of 4561 pregnancies from women with asthma who delivered between 1990 and 2000 was reconstructed. A two-stage sampling cohort design was used to acquire additional data from the woman’s medical chart. Cases of congenital malformation were identified from the medical services database or the hospital database. Using refill patterns of medications, the average daily dose of ICSs used during the first trimester was calculated and categorised as follows: 0, 1–500, 500–1000 and >1000 μg/day in beclomethasone–chlorofluorocarbon equivalent. A Generalized Estimation Equation model was used to estimate the adjusted odds ratio of congenital malformation as a function of ICS daily dose. All analyses were performed for all malformations and major malformations separately. Results: Within the cohort 418 babies were identified with a congenital malformation (9.2%), 278 of which had a major malformation. About 40% of women used ICSs during the first trimester, but only 5.3% of women used >500 μg/day. The adjusted odds ratio (95% CI) for all malformations associated with the use of ICSs during the first trimester was: 0.77 (0.53 to 1.13) for 1–500, 0.41 (0.19 to 0.92) for 501–1000 and 1.00 (0.42 to 2.36) for >1000 μg/day. The corresponding figures for major malformations were 0.90 (0.64 to 1.24), 0.56 (0.22 to 1.43) and 1.67 (0.56 to 5.03). Conclusion: This study adds evidence to the safety of ICSs for the treatment of asthma during pregnancy, with regard to the likelihood of congenital malformation.

HIV risk profile and prostitution among female street youths

The objective of this study was to compare human immunodeficiency virus (HIV) risk factors among female street youths involved in prostitution and those with no history of prostitution. Youths aged 14 to 25 years were recruited into the Montreal Street Youth Cohort. Semiannually, youths completed an interviewer-administered questionnaire. Statistical analyses comparing characteristics and HIV risk factors for girls involved in prostitution and those never involved were carried out using parametric and nonparametric methods. Of the girls, 88 (27%) reported involvement in prostitution, and 177 girls reported no history of prostitution at the baseline interview. Girls involved in prostitution were two times and five times more likely to have reported bingeing on alcohol and on drugs, respectively. A history of injection drug use was four times more likely to have been reported by girls involved in prostitution. Further, these girls were 2.5 times more likely to have reported injected cocaine as their drug of choice. Girls involved in prostitution were younger the first time they had consensual sex and were twice as likely to have reported anal sex. Consistent condom use for anal, vaginal, and oral sex was low for all girls. Girls involved in prostitution reported more risky sexual partners. In conclusion, girls involved in prostitution may be at increased risk of HIV infection due to their injection drug use and risky sexual behaviors. Unique intervention strategies are necessary for reducing HIV infection among female street youths involved in prostitution.

Agreement between administrative databases and medical charts for pregnancy-related variables among asthmatic women†

To determine the validity of pregnancy variables recorded in administrative databases of Quebec using patient medical charts as the gold standard among asthmatic pregnant women.