A predictive model for venous ulceration in older adults: results of a retrospective cohort study

Although venous leg ulcers (VLU) are a common health concern for many older adults, knowledge about common risk factors and optimal screening methods remains limited. To determine risk factors and develop a predictive model for future venous ulceration, a retrospective cohort study of clinical outpatients >60 years old in a primary care panel in Olmsted County, MN (N = 12,650) was conducted. The primary outcome was a new diagnosis of VLU within 2 years of the study date (January 1, 2005). Risk factors included demographic and comorbid health risk factors. The average age of study participants was 72.7 years (SD 8.9) and the incidence of VLU was 1.7% - 8.6 cases per 1,000 patient-years. The most significant risk factor was a history of venous ulceration (OR 19.4; 95% CI 14.5-25.9). In the final multivariate logistic regression model, a history of venous ulceration (OR 18.66; CI 13.96-24.96, P < .0001), renal insufficiency (OR 2.24; 95% CI 1.60-3.15, P <.0001), cataracts (OR 1.64; CI 1.16-2.33, P = 0.01), blindness (OR 2.53; 95% CI 1.05-6.11, P = 0.04), and pressure ulceration (OR 2.36; 95% CI 1.26-4.45, P = 0.01) remained significant as risk factors for VLU. Using the odds ratios from the predictors in the final multivariable mode, a scoring model for the entire cohort was created and a scoring model for each subject was run for the final model. The area under the receiver operator curve was 0.797 with a cutoff score of 3. Prior venous ulceration remains the most important risk factor for future venous ulceration. Further study and application of the risk assessment model to substantiate its clinical value are warranted.