Unexpected factors predict control of hypertension in a hospital-based homeless clinic

Background: Boston Health Care for the Homeless Program (BHCHP) physicians conduct a primary care clinic twice a week at Massachusetts General Hospital (MGH). The MGH clinic is part of a citywide network of BHCHP clinics providing primary care services to indigent patients. Despite this network long term control of chronic illnesses such as hypertension (HTN) continues to challenge the clinic staff. Methods: In an effort to better understand the factors obstructing long term treatment of chronic illnesses, we conducted a chart review of hypertensive patients seen over a three-year period (January 1991 to March 1994) at the MGH clinic. Frequency of visits, total number of visits and physicians' notes on concomitant diagnoses were analyzed for their correlation to control of hypertension. Results: Overall control of hypertension was poor (42%). A greater proportion of patients with a diagnosis of psychiatric illness responded to treatment intended to lower their blood pressure below 140/90 mm Hg than those without such a diagnosis (odds ratio: 10.2). While there was no difference in the total number of clinic visits during the study period, those with a diagnosis of psychiatric illness had a lower average number of days between their first and third visits (52 days vs 108 p=0.002). Conclusions: A greater proportion of patients with concomitant psychiatric diagnoses exhibited blood pressures less than or equal to 140/90 mm Hg than patients without mental illness. The increased frequency of visits at the onset of treatment may confer a positive effect on long term control of HTN among homeless patients attending outpatient hospital-based clinics.