A retrospective analysis of the prevalence and treatment of hypertension and dyslipidemia in Southwestern Ontario, Canada

Background: Previous evaluations of the Southwestern Ontario (SWO) cohort have reported that hypertension (HTN) and dyslipidemia (DYS) are under-treated illnesses; however, concomitant treatment is unknown. Objectives: The objectives of this study were to assess the prevalence and associated treatment of HTN and DYS in primary health care in SWO and to identify care gaps across subpopulations. Methods: In this retrospective cohort analysis, chart-abstracted medical records of patients aged 48 years with a clinical diagnosis of HTN, DYS, or both and the clinical practice records of primary health care facilities in London, Ontario, Canada, and the surrounding area were conducted between April and December 2000; longitudinal updates were performed quarterly until December 2004. Chart-abstracted information included demographics, lifestyle (eg, diet, exercise), cardiovascular disease indicators, complete morbidity profile, and drug treatments and effects. Results: The medical records of 46,322 patients who received medical care and the clinical practice records of 37 primary health care facilities (where the patients received treatment) in London, Ontario, Canada, and the surrounding area were included in this study. Our analyses found that the prevalence of HTN (17.6%) was greater than that of DYS (12.3%); with comorbid HTN and DYS found in 8.0% of the population. Most hypertensive patients were not dyslipidemic (54.8%), but more than half of dyslipidemic patients had comorbid HTN (64.9%). Significant differences in prevalence among the sex, age, and comorbid subgroups were found. HTN was higher among females than males (P < 0.001) but lower among female smokers than male smokers (P < 0.001). Patients aged >55 years were much more likely to be hypertensive, dyslipidemic, or both compared with those aged <55 years (P < 0.009), except among those patients with a family history of coronary heart disease (CHD). Additionally, a steady increase in HTN and DYS prevalence with age by decade until 75 years of age, after which the rates dropped off, was observed. Most patients were untreated for HTN (66.0%) or DYS (80.0%) unless both conditions were present (35.0% untreated for HTN; 39.0% untreated for DYS). Among patients with comorbid HTN and DYS, the order of diagnosis had a significant effect on treatment level. The presence of other comorbidities (eg, family history of CHD) resulted in higher treatment and control rates. Control levels were generally poor, with 7.0% among patients with DYS, 15.0% among patients with HTN, and 17.0% among patients with both conditions. Conclusions: Treatment patterns of HTN and DYS in practice settings are not in alignment with current guidelines in this cohort. Pharmacologic treatment of HTN and DYS is underprescribed. Patients most likely to receive treatment have comorbidities,. but even in those high-risk groups, treatment levels are low and recommended control levels even lower.