Spa therapy had proven his efficiency with good safety. Very few studies have been conducted among older subjects (over 60 years old) with musculoskeletal disorders. The objective of this study is to measure the effect size on pain of a spa therapy treatment in a chronic low back pain population aged 60 to 80 years.

A prospective study was conducted at Neyrac-les-Bains spa therapy resort (France) from August to November 2015. Included subjects benefited 3-weeks conventional cure. Measurements were made at D0, D18, M3 and M6. The primary endpoint was pain on a numerical scale at 3 months. The secondary outcomes were disability on the Oswestry Disability Index (ODI) and use of NSAIDs and analgesics.

Seventy-eight patients were included. Mean pain was significantly improved (P<0.001) at 3 months: 48.8 (± 19.9) vs. 39.1 (±20.5), effect size for pain was 0.43 [0.21, 0.66]. The mean ODI significantly changed (P<0.001) to 3 months: 43.5 (±10.6) vs. 39.4 (±9.5), with an effect size of 0.40 [0.17; 0.62]. Intake of NSAIDs and paracetamol significantly decreased at 3 months, respectively −12.8% (P<0.0075) and-17.9% (P<0.0005). Drugs intake reduction was maintained at 6 months follow up.

This study shows that a conventional spa therapy treatment is an effective treatment for pain, function and intake reduction of NSAID and analgesic for the elderly chronic low back pain (60–80 years) patients. It highlights a modest effect size of the spa therapy, and we were not able to define explanatory factors for a good response. The definition of the effect size of this type of intervention can be used as a basis for future randomized controlled trials.