Pain. 1997 Apr; 70(2-3): 203-8.

Diminishing returns or appropriate treatment strategy?--an analysis of short-term outcomes after pain clinic treatment.

Davies HT, Crombie IK, Brown JH, Martin C.

Department of Management, University of St Andrews, St Katharine's West, The Scores, Scotland, UK. hd@st-and.ac.uk

In the United Kingdom patients with chronic pain are frequently managed in anaesthetist-led outpatient pain clinics. In many of these clinics the emphasis is on medical therapies (analgesics and psychotropic drugs, TENS, acupuncture and nerve blocks) with patients trying a series of different therapies until relief is achieved or further attempts at physical treatments are discontinued. The sequential trial of different treatment modalities presents clinicians with a problem. Patients who receive little benefit from (say) the first three treatments tried might be expected to be less likely to gain benefit from the next treatment modality. The presence or absence of such 'diminishing returns' from treatment will influence when therapeutic efforts based on the medical model of pain should be abandoned. This study examined basic outcome data on 1912 patients seen in a single Scottish pain clinic between 1987 and 1994. The data were analysed to assess whether the success of treatment modalities depended on whether they were used as a first-choice treatment or were given after previous therapeutic attempts had failed. Diminution in success rates was generally not large although this varied between therapies. No fall-off in success rates was seen for antidepressants, acupuncture or sympathetic nerve blocks. However, the other nerve blocks all showed falling success rates when they were used as fourth- or fifth-line treatments. That little diminution of success rates was seen warrants further investigation. Pain clinics need good information on the success or otherwise of late treatment so that they can devise rational pain management strategies covering multiple therapies and appropriate criteria for ending medical interventions. These findings suggest that allowing patients access to multiple pain therapies may well be an appropriate management strategy.