Association of Clinical Quality Measures and Cardiovascular Disease Mortality in Minnesota Primary Care Service Areas *

BACKGROUND:  Widespread adoption of clinical quality measures for public reporting has expanded beyond inpatient hospital to outpatient clinical settings.  Minnesota has been a leader in the development of public reporting of quality measures in the clinic setting.  Voluntary reporting of a clinical quality measure for diabetes began in 2003, and Optimal Vascular Care (OVC), a similar quality measure for vascular disease, was first reported the following year.  Minnesota’s Health Reform legislation enacted in 2008 required that hospitals and clinics report clinical quality measures to the State annually, including OVC.  Aggregate measures are publicly-reported for individual clinics and are used to improve clinical quality and guide consumer decision making.  This project explores the public health surveillance application of clinical quality measures for exploring linkages between quality of cardiovascular disease care and mortality.

METHODS:  The 2010 OVC measure from all reporting clinics (n=576) was recast to the patients' residential zip code.  ANOVA was used to compare OVC rates to age-adjusted major cardiovascular disease mortality rates for 2010 after aggregating zip code level data to Primary Care Service Areas (PCSA) as defined after the 2000 US Census.  Demographic and population characteristics were extracted from the 2010 US Census and American Community Survey 2008-2012 for Zip Code Tabulation Areas (ZCTAs).

RESULTS: During 2010, Minnesota PCSAs with at least 10 cardiovascular deaths (n=140) had OVC rates ranging from 0.08 to 0.54; the median for all PCSAs was 0.35, and the statewide rate was 0.50.  There was a significant positive association between college education and foreign born prevalence with the OVC.  After adjustment for these demographic covariates, a strong inverse association remained between the age-adjusted mortality rate for major cardiovascular disease and OVC rate in Minnesota PCSAs.  In the lowest OVC rate tertile, the age-adjusted mortality rate was 207.9 per 100,000 (95% C.I.: 194.5-221.3), compared to 175.4 (162.3-188.4) for the highest OVC tertile.   This adjustment did not significantly alter the univariate association.  Minneapolis-St. Paul PCSAs had the highest OVC rates and lowest mortality.  

CONCLUSIONS:  This work is the first to demonstrate an association between publicly-reported clinical quality measures for vascular disease patients and overall cardiovascular disease mortality at the community-level for an entire State.  Clinical quality measures bolster surveillance of cardiovascular disease in small geographic areas, and help identify communities for targeted interventions to improve the quality of clinical care and, potentially, overall cardiovascular disease mortality.  Future work includes longitudinal investigations of clinical care quality measures and cardiovascular disease mortality.