Outdoor air pollution improves the validity of a screening scale for cardiovascular disease (CVD) in clinical settings

Background Cardiovascular disease (CVD) is one of the leading causes of demises reported in the 21st century. Objective Our objective is to develop a screening score to estimate the probability of cardiovascular events, stressing on the importance of including outdoor air pollution to improve the validity of the scale among the Lebanese adult population. Methods A case–control study was carried out between October 2011 and October 2012 comparing CVD cases to a control group (Sample 1). Two multivariate analyses using logistic regression were carried out to evaluate predictors of the dependent variable. The second model included the outdoor air pollution variables, while the first did not. The adjusted odds ratios (OR) obtained were rounded to the nearest units and used as coefficients in the generated scales. Following the scale set up, a second case–control of 200 patients was also performed for clinical validation (Sample 2). Results Our study showed that the scale for screening of CVD, which included outdoor air pollution variables, can foresee the CVD outcomes better than the score using only the traditional CVD risk factors. The areas under the curve were 0.737 (0.692–0.882; P < 0.001) and 0.864 (0.825–0.903; P < 0.001), respectively. Our results also provide some evidence of the clinical validity of the scale. Conclusion This screening scale could detect subjects at elevated risk for CVD in the clinical settings.