Concurrent Session 2 – Oral Presentations: Clinical Challenges

Use of SSRI Antidepressants in Pregnancy: Is There Evidence of Benefit?

Presenting Author: Dr. Barbara Mintzes, Therapeutics Initiative, University of British Columbia
Co-authors: Patricia Fortin, Therapeutics Initiatives, University of British Columbia; Dr. Jon Jureidini, University of Adelaide, South Australia; Dr. Tim Oberlander, Department of Developmental Pediatrics, University of British Columbia

Background: SSRI antidepressants are commonly used in pregnancy in Canada. Pregnant women and their carers face conflicting advice: on the one hand, they are warned of risks of malformations and a neonatal syndrome at birth; on the other hand, use is recommended as untreated depression may lead to harm.

Objectives: The aim of this systematic review was to determine whether there is evidence of a net benefit to maternal or infant health from the use of SSRI antidepressants in pregnancy for the treatment of depression, as compared with placebo, non-drug options, or no treatment.

Approach: Randomized controlled trials, controlled cohort and case-control studies comparing outcomes in pregnant women with depression with and without SSRI use were included. Data were extracted via a standardized form, and meta-analysis carried out where applicable using RevMan 5.

Results: Eight studies met inclusion criteria; all compared SSRIs with no treatment. Risks of bias included convenience samples (n = 5), baseline differences, lack of blinding, and limited reporting. There was no evidence of benefit from SSRI use in higher quality studies or all studies, and no improvement in maternal functioning, quality of life, or prevention of post-partum depression. Compared with no treatment, SSRIs led to more respiratory distress (RR = 1.6 (95% CI 1.2-2.1), more cardiac malformations (RR = 2.1 (95% CI 1.3-3.2), and a mean of 4.6 days (95% CI 1-8) earlier births.

Conclusions: We found no evidence that SSRIs prevent harmful sequelae of depression in pregnancy. Given the potential for harm, these results call into question current approaches to care, and support the need for better integration of non-drug options.

Evaluating Change in National Breast Screening Performance Indicators Following the Implementation of Full Field Digital Mammography (FFDM)

Presenting Authors: Dr. Jennifer Payne, Dalhousie University
Co-authors: Gerry Schaller, QE II Health Sciences Centre; Judy Caines and Stephanie Lea, Nova Scotia Breast Screening Program

Objective: To describe changes in several national breast screening performance indicators following the transition from analogue to full-field digital mammography (FFDM) in Nova Scotia.

Methods: The study design is a repeated cross-section of women screened through five fixed sites of the Nova Scotia Breast Screening Program in the six-month period of analogue mammography use immediately prior to FFDM implementation compared with women screened in a similar period of FFDM in the same sites, allowing for a transition period to the new technology. Analyses are presented by 10-year age group for the following performance indicators: abnormality rate, benign: malignant on surgery, positive predictive value, and cancer detection rate.

Results: Preliminary results suggest a lower abnormality rate following implementation of FFDM and that this difference increases with younger age. In contrast, a higher cancer detection rate was observed, as well as an improvement in the benign: malignant ratio. The most marked changes in performance indicators were consistently among women aged 40 to 49.

Conclusions: The implementation of FFDM is associated with a significant improvement in the ability to screen for breast cancer, particularly among women aged 40 to 49. The decision to implement FFDM on a province-wide basis will result in more effective detection of breast cancer among Nova Scotia women.

Cost-effectiveness Analysis of Primary and Secondary Prevention Programs of Cervical Cancer in Canada

Presenting Author: Orges Ormanidhi, Toronto Health Economics and Technology Assessment Collaborative; Dr. Chris Bauch, University of Guelph
Co-authors: Ba’ Pham and Dr. Murray Krahn, Toronto Health Economics and Technology Assessment Collaborative; Dr. Lawerence Paszat, Institute for Clinical Evaluative Sciences

Background: In Canada, cervical screening is opportunistic, with varied intervals (every year or two to three years) and annual coverage rates (12% to 74%) across geographical and socio-economic regions. Public immunization program for nine- to 13- year-old females with the quadrivalent HPV vaccine was implemented in 2007, with vaccination coverage varying from 50% to 90%. Consequently, screening programs are being re-evaluated.

Objective: To evaluate the effectiveness and cost-effectiveness of (1) modified screening programs (e.g., liquid-based cytology, primary HPV-testing with cytology triage, five-year interval, late screening, and early stoppage); (2) combined primary and modified secondary prevention programs; and (3) targeted vaccination programs for low screening coverage areas.

Methods: The CEA used a society perspective. A dynamic heterosexual partnership network model, stratified by age, gender, and risk group, and projecting HPV incidence, was integrated with a validated disease history model of HPV infection and cervical cancer (CC). Input data were derived from population-based, linked administrative data sources. A Monte Carlo approach to calibration was used to integrate the two model components.

Results: Preliminary results (not yet accounting for effects of vaccination) show that two-year screening strategies using HPV triage, with or without liquid-based cytology, represents the best use of resources for CC screening in non-vaccinated Canadian women. It requires 1,134 women to be screened every two years over a lifetime to avoid one CC case and 3,023 women to prevent one CC-related death.

Conclusion: We use the above modelling and health economic approach to explore the best use of resources for primary and secondary Canadian prevention programs.

Economic Evaluation of Dose-Response Resistance Training in Older Women: A Cost- Effectiveness and Cost Utility Analysis

Presenting Author: Jennifer Davis, University of British Columbia
Co-authors: Dr. Carlo Marra, Dr. Clare Robertson, Professor Karim Khan and Assistant Professor Teresa Liu-Ambrose, University of British Columbia

Objective: To estimate the incremental cost-effectiveness and cost utility of a once-weekly or twice-weekly resistance training intervention compared with twice-weekly balance and tone classes in terms of falls prevented and quality-adjusted life-years gained.

Design: Economic evaluation conducted concurrently with a three-arm randomized controlled trial.

Setting: Community-dwelling older women.

Participants: One hundred and fifty-five women aged 65 years to 75 years, Mini-Mental State Examination ≥ 24, and visual acuity 20/40 or better.

Intervention: Fifty-four participants received the once-weekly resistance training, 51 participants received the twice-weekly resistance training, and 50 participants received the twice-weekly balance and tone classes (the comparator).

Main outcome measures: Number of falls for each participant, health care resource utilization and associated costs over nine months, health status assessed using the EQ-5D and SF-6D at baseline, six months, and 12 months to calculate quality-adjusted life-years.

Results: Total health care costs were significantly lower for the once-weekly resistance training and twice-weekly resistance training groups compared with the twice-weekly balance and tone (comparator) group (p < 0.05). From the Canadian health care system perspective, the incremental cost-effectiveness ratios ($ per fall prevented) for both the once- and twice-weekly resistance training dominated twice-weekly balance and tone (comparator) classes.

Conclusion: An individually tailored resistance training intervention delivered once or twice weekly provided better value for money for falls prevention than balance and tone classes.