Patient-Physician Language Concordance, Antihypertensive Medications, and Cardiovascular Outcomes Among Allophone-Speaking Patients with Hypertension.

Background: Patient-physician language concordance is associated with better outcomes. However, the mechanism(s) explaining these associations are poorly understood. Our objective was to determine if antihypertensive medication use mediates the association between patient-physician language concordance and major adverse cardiovascular events (MACEs). Methods: Our population-based, retrospective cohort study used data from the Canadian Community Health Survey (CCHS) from January 1, 2003 to December 31, 2014. We identified Allophone-speaking respondents (ie, the language spoken most often at home is one other than English, French, or an Indigenous language) with self-reported hypertension. We defined patient-physician language concordance as agreement between language spoken most often at home and language spoken with one's regular medical doctor. Survey responses were linked to hospitalization and mortality records. We identified all MACEs within 5 years after survey completion. The associations between patient-physician language concordance, antihypertensive medication use, and MACEs were explored using multivariable logistic and Cox proportional hazards regression, respectively. The mediating effect of antihypertensive medication use was tested with natural effect models. Results: We studied 5013 Allophone-speaking patients, including 1708 (34.1%) who received language-concordant care and 3305 (65.9%) who received language-discordant care. Patients who received language-concordant care were 38% less likely to experience a MACE compared to patients who received language-discordant care (hazard ratio 0.62, 95% confidence interval 0.48-0.80). No evidence was found that this association was mediated by antihypertensive medication use. Conclusions: Patient-physician language concordance was associated with a lower risk of a MACE. However, this association was not mediated by antihypertensive medication use. Further research could explore potentially modifiable mediators of this association.