Identifying episodes of back pain using medical expenditures panel survey data: patient experience, use of services, and chronicity.

OBJECTIVE: To explore the correspondence between "Episodes-of-Pain" and "episodes of care" for individuals with back pain.
METHODS: This study was a secondary analysis of Medical Expenditures Panel Survey (MEPS) 2-year longitudinal data. Individual use and utilization of back pain services were examined across ambulatory settings and providers, and linked to MEPS medical condition data to identify individuals with back pain who do not use or who delay or discontinue utilization of health services for back pain. "Episodes-of-Care" and Episodes-of-Pain were approximated through round-by-round temporal mapping of MEPS back pain utilization events data and medical conditions data.
RESULTS: Of 10,193 individuals with back pain, approximately one fifth did not actively seek care for their back pain. Utilization of services for back pain (Episodes-of-Care) does not always correspond with an individual's full experience of back pain (Episodes-of-Pain). Upwards of 20% of MEPS respondents who use services for some back pain episodes, reported additional episodes for which they do not use services.
CONCLUSIONS: These findings suggest that other longitudinal studies based only on data that reflect service use, for example, claims data, may incorrectly infer the nature of back pain and back pain episodes. Many individuals report ongoing back pain that continues beyond their Episodes-of-Care, and many individuals with persistent back pain may use prescription drugs, medical services, and other health services only intermittently.