Creating and using the CDC HRQOL healthy days index with fixed option survey responses

"Healthy days" are calculated by adding the number of poor physical and mental health days and subtracting the total from 30 days using the US Centers for Disease Control and Prevention Health-Related Quality of Life (HRQOL) scale. This study sought to compute the index with forced responses and hypothesized significant HRQOL differences with demographic and risk behavior variables would be observed.

Using the 1997 South Carolina YRBS and a 2007 university data set, variables were created based on the averages within each response option from the index items (e.g., 1-2 days would assigned as 1.5 days, etc.). Then the greater of the two values in each respective cell (poor physical or mental health days) was chosen for the analysis.

Although some differences existed between the two samples, the same general pattern of responses was established. Significant HRQOL differences were observed among selected demographic, substance use, weight perception, and self-rated health variables (P < .05).

Preliminary evidence suggests the "healthy days" calculation is a valid approach with fixed option responses.