Value of Patient Time Invested in the Colonoscopy Screening Process: Time Requirements for Colonoscopy Study

Purpose. Previous cost-effectiveness analyses of colorectal cancer screening have not considered the value of patient time despite consensus recommendations to do so. The authors sought to estimate the amount and value of patient time required for screening colonoscopy. Methods. Patients who were scheduled to undergo screening colonoscopy were recruited from a university endoscopy center. Participants completed a time diary for the screening colonoscopy process, including time spent in preparation, travel, waiting, colonoscopy, and recovery. The authors defined several time intervals and estimated their value. The primary time interval of interest, called occupied time, included preparation, travel, waiting, the colonoscopy procedure, and on-site recovery. Time was valued at the 2005 average wage rate. The authors performed sensitivity analyses to test other time intervals and wage rates. They then incorporated patient time costs into a previously published cost-effectiveness analysis of colorectal cancer screening to examine their impact. Results. One hundred ten subjects completed the study. The sample was 57% female, 85% Caucasian, and 90% insured (40% Medicare, 4% Medicaid). The mean occupied time was 23.2 hours, worth $432 at the average wage rate. The authors estimate that including patient time costs in cost-effectiveness analysis would increase the cost per life-year saved with screening colonoscopy by 68%, from $13,100 to $22,000. Sensitivity analyses showed that the increase could range from 17% to 224% depending on the time interval valued. Conclusions. Patient time constitutes an important cost in colonoscopy screening and should be included in cost-effectiveness analyses.