What factors explain the number of physical therapy treatment sessions in patients referred with low back pain; a multilevel analysis

Data were used from a national registration network on physical therapy. Our database contained information on 1,733 patients referred with LBP, treated by 97 therapists working in 41 practices. The variation in the number of treatment sessions was investigated by means of multilevel regression analyses.Eighty-eight per cent of the variation in the number of treatment sessions for patients with LBP is located at patient level and seven per cent is located at practice level. It was possible to explain thirteen per cent of all variance. The duration of the complaint, prior therapy, and the patients' age and gender in particular are related to the number of physical therapy treatment sessions.Our results suggest that the number of physical therapy treatment sessions in patients with LBP mainly depends on patient characteristics. More variation needs to be explained, however, to improve the transparency of care. Future research should examine the contribution of psychosocial factors, baseline disability, and the ability to learn motor behavior as possible factors in the variation in treatment sessions.It is well-known that the number of physical therapy treatment sessions varies over treatment episodes [1-10] and it is important for health care policy makers, physical therapists and patients to gain greater understanding of the sources of this variation. Greater understanding will increase the transparency of care and can provide novel insights into the quality of care. On grounds of equity, an 'ideal' situation is one where health status is the main determinant of treatment choice and hence of variation. As a consequence, the variation is appropriate when it occurs due to 'need' factors like the patient's clinical health status [11], but it is questionable whether the variation is appropriate when it occurs due to factors like social structure, health beliefs, or enabling resources (such as accessibility). Elimination of inappropriate variation is necessary for quality