Data equivalency of an interactive voice response system for home assessment of back pain and function

BACKGROUND: Interactive voice response (IVR) systems that collect survey data using automated, push-button telephone responses may be useful to monitor patients' pain and function at home; however, its equivalency to other data collection methods has not been studied. OBJECTIVES: To study the data equivalency of IVR measurement of pain and function to live telephone interviewing. METHODS: In a prospective cohort study, 547 working adults (66% male) with acute back pain were recruited at an initial outpatient visit and completed telephone assessments one month later to track outcomes of pain, function, treatment helpfulness and return to work. An IVR system was introduced partway through the study (after the first 227 participants) to reduce the staff time necessary to contact participants by telephone during nonworking hours. RESULTS: Of 368 participants who were subsequently recruited and offered the IVR option, 131 (36%) used IVR, 189 (51%) were contacted by a telephone interviewer after no IVR attempt was made within five days, and 48 (13%) were lost to follow-up. Those with lower income were more likely to use IVR. Analysis of outcome measures showed that IVR respondents reported comparatively lower levels of function and less effective treatment, but not after controlling for differences due to the delay in reaching non-IVR users by telephone (mean: 35.4 versus 29.2 days). CONCLUSIONS: The results provided no evidence of information or selection bias associated with IVR use; however, IVR must be supplemented with other data collection options to maintain high response rates.