BACKGROUND: The purchasing arrangements for acute low back pain recommended to UK health ministers by the Clinical Standards Advisory Group (CSAG) in 1994 as a cost-neutral way of reducing back pain disability have not been tested in practice.

OBJECTIVE: To test the CSAG's recommendations in primary care, studying their cost implications and identifying the professional relationships between general practitioners (GPs) and manipulation practitioners.

DESIGN: Retrospective and prospective observational study with cohorts balanced for similar features in terms of age, gender, diagnosis, severity and work loss at entry point.

PARTICIPANTS: One hundred and ninety-four retrospective patients with acute low back pain presenting to 11 GP practices between July and October 1995. Three hundred and forty-four prospective patients with the complaint presenting to the same practices between November 1995 and March 1996. Referrals to local chiropractic, osteopathic and manipulation physiotherapy practices as well as to usual secondary care services.

OUTCOME MEASURES: Waiting time for first attendances, sickness certification, number of consultations, drug use and costs, recovery time, x-ray utilization, cost of care.

MAIN RESULTS: Substantial shift of referrals to manipulation practitioners under the scheme. Prospective patients had fewer referrals to secondary care than retrospective patients, fewer GP consultations, less drug use, fewer certified sickness days. Prospective patients had shorter waiting times to be seen by manipulating physiotherapists. Chiropractors used X-rays more often than other practitioners. Demonstrable savings in sickness incapacity benefits were evident by following CSAG recommendations.

CONCLUSION: GPs complied with CSAG management recommendations when funding of manipulation services was made available. Implementation was associated with better outcomes generally. A fully funded study including chronic back patients is justified.