Impact of precipitating events on pediatric chronic pain recovery

OBJECTIVES: 1) To measure the prevalence of precipitating events in pediatric chronic pain patients and 2) to compare pain and functional disability outcomes at evaluation and 4-month follow-up by presence and type of precipitating event. METHODS: Precipitating events (e.g., injury) were coded from the medical record for 401 youth (6-19) who presented to a tertiary care chronic pain clinic. Four-month follow-up disability and pain were collected for 187 patients. In addition to frequency of events, we examined differences in pain and disability measures by event type at evaluation and follow-up using multiple statistical analysis strategies. RESULTS: Two-thirds of patients had a precipitating event prior to pain onset. Injury was the most common (55%), followed by chronic disease (23%), infection/illness (12.8%), and surgery (7.5%). Patients whose pain was triggered by injury reported the highest average pain levels, F(3, 340)=2.67, p<.05 and functional disability, F(3, 295)=3.54, p<.05. There were multiple cases of event groups that had significantly different baseline and follow-up psychological measures when compared to the rest of the patient population. Trajectories of pain and disability did not differ between patients with and without a precipitating event. Patients with injuries reported greater improvement in functional disability at follow-up (time x injury) F(1, 183)=4.88, p<.05 whereas patients with chronic disease reported less improvement in disability (time x chronic disease), F(1, 183)=5.49, p<.05. No other interactions were significant for disability or pain. CONCLUSIONS: A majority of patients had experienced some form of precipitating event prior to their pain onset, and the presence of a precipitating event had varied effects on the treatment outcomes of patients at four-month follow-up. Although patients with injuries presented with greater disability and pain, they had significantly more improvement, while chronic disease patients were less likely to improve in terms of functional disability. Type of precipitating event appears to be associated with treatment response and can inform clinical prognoses