The comparative effectiveness of chiropractic on function, health, depressive symptoms, and satisfaction with care among medicare beneficiaries

Musculoskeletal complaints are one of the most common reasons for visits to medical and chiropractic professionals in the United States, and spine-related symptoms in particular comprise the largest share of these complaints. Spine-related conditions increase as people age, having implications for rising disability and consequent spending by Medicare and Medicaid on increased health services use and long-term services and support. Chiropractic is one type of treatment used by older adults with these types of health problems. Covered by Medicare since 1972, chiropractic spinal manipulation is allowed for the express purpose to arrest the progression of functional decline or restore and possibly improve patient function. No studies, however, have examined whether chiropractic use by Medicare beneficiaries has indeed arrested functional decline, delayed disability, or restored health. The purpose of this dissertation research is to examine the comparative effectiveness of chiropractic use relative to no treatment and alternative medical care on the health and functional trajectories of community-dwelling older adults. I also examine the comparative effect of chiropractic on satisfaction with care. This is accomplished through the use of two longitudinal surveys with representative Medicare populations linked to Medicare provider claims. The first analysis examines the long-term comparative effect of chiropractic relative to no use and alternative care on functional decline, self-rated health decline, and the onset of additional depressive symptoms in a cohort of older Medicare beneficiaries, both with and without back conditions. The second study examines the effect of chiropractic compared to medical only episodes of care on health and functional decline in an older adult population with uncomplicated back conditions over a two-year period. The third and final study examines the comparative effect of chiropractic relative to medical care only on one-year changes in function, self-rated health, and satisfaction with care in a nationally representative age-eligible Medicare population with spine-related musculoskeletal conditions.

Study results suggest that chiropractic has a consistently protective effect when compared to routine alternative medical care against decline in function among older adults with spine-related conditions, both over the long-term and the short-term. Chiropractic also has a comparative protective effect against decline in self-rated health in the short-term, but has no differential effect on the onset of depressive symptoms either in the short-term or long-term . Medicare beneficiaries using chiropractic for spine-related health conditions are relatively more satisfied than those using medical care only with the information provided to them about their condition, and with follow-up care provided after the initial visit.

This research is the first of its kind to examine the comparative effectiveness of chiropractic relative to other usual sources of care for Medicare beneficiaries, in general and specifically among those with spine-related conditions, finding that chiropractic use has a comparatively beneficial effect on function, health, and satisfaction with care. The results have important policy implications for clinicians, patients, and Medicare because of the potential to shift clinical practice away from technologically intense and expensive treatments toward therapies like chiropractic spinal manipulation that demonstrate a comparative advantage in preserving health and function among older adults.