ARE SELF-REPORTED PAIN CHARACTERISTICS, CLASSIFIED USING THE PAINDETECT QUESTIONNAIRE, PREDICTIVE OF OUTCOME IN PEOPLE WITH LOW BACK PAIN AND ASSOCIATED LEG PAIN?

Purpose of study and background

This study aimed to investigate if the PD-Q classification was predictive of outcomes at 3 and 12-months follow-up in LBP patients with associated leg pain.

Identification of clinically important subgroups and targeted treatment is believed to be important in low back pain (LBP) care. The PainDETECT Questionnaire (PD-Q) is designed to classify whether a person has neuropathic pain, based on their self-reported pain characteristics. However, it is unknown whether this classification is a prognostic factor and/or predicts treatment response.

Method and results

145 participants were recruited in secondary care. Inclusion criteria were 3-12 months LBP and leg pain. Baseline PD-Q scores classified participants into three groups (likely to have neuropathic pain, uncertain, unlikely) but did not affect treatment decisions. The outcome measures were LBP, leg pain, activity limitation and self-reported general health. Scores were compared between those with ‘likely’ neuropathic pain (neuropathic group) and ‘unlikely’ (non-neuropathic group), using Mann-Whitney, Friedman and Chi Square tests.

At baseline, the neuropathic group had worse scores on all outcome measures, and analgesic use, sick leave, sense of coherence and psychological profile (p=.000 to .044). At 3-months and 12-months both groups improved (p=.001 to .032). However, the groups remained different at each time point on all outcome measures (p=.000 to .033) except LBP (p=.054 to .214).

Conclusions

The PD-Q classification was a prognostic factor but was not predictive of response to generic care. Further studies should investigate whether PD-Q groups are predictive of response to neuropathic pain targeted treatment.