Prescription Trends of Thiazide Diuretics in a Canadian Primary Care Population From 2015 to 2021
Bibliographic record
Abstract
Background: Hypertension Canada 2017 guidelines favoured the use of thiazide (TZ)-like diuretics, such as CLTD (chlorthalidone) and indapamide (IND) over hydrochlorothiazide (HCTZ). Health Canada warned in 2019 that HCTZ may be associated with increased risk of skin cancer. Our study looked at the changes in TZ prescriptions from 2015 to 2021 in Ontario, Canada. Methods: A retrospective cohort study was conducted of adults with hypertension, using electronic medical record data from the University of Toronto Practice-Based Research Network database covering mostly the Greater Toronto area. Outcomes included the proportion of patients who received a prescription of HCTZ, CLTD, or IND each month. Interrupted time-series analysis was used to evaluate the change in outcomes after publication of the 2017 guidelines and 2019 safety warning. Prescription trends were stratified by prescribing physicians' sex and year of medical school graduation. Results: A total of 100,428 patients with hypertension were included in the cohort, with 31,700 patients who received at least one TZ prescription from 343 family physicians. We found a declining trend in HCTZ prescriptions over time, accompanied by an increase in IND and CLTD prescriptions, with statistically significant but transient changes in prescription rates after publication of the 2017 guidelines and the 2019 safety warning for all 3 medications. Female physician and early-career physician prescription rates changed faster than that of their counterparts immediately after the Health Canada safety warning was issued. Conclusions: TZ diuretic prescription patterns have changed in recent years, but Hypertension Canada's 2017 guidelines and the 2019 Health Canada safety warning did not have a sustained significant impact on the change in prescription rates of HCTZ, IND, and CLTD.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.002 | 0.005 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".