Background: Few studies have evaluated the epidemiology and effect of pain in ambulatory patients with cancer who are undergoing active therapy. This information is needed to develop strategies for supportive care in this population.
Methods: The prevalence and characteristics of pain were determined in a prospective survey of ambulatory patients with lung or colon cancer. To reduce bias and acquire comprehensive information, the methodology used face-to-face interviews by trained quality assurance analysts, a multifaceted assessment instrument, and multivariate statistical analysis.
Results: In a telephone interview, "persistent or frequent" pain during the previous 2 weeks was reported by 57 of 145 (39.3%) patients with lung cancer and 52 of 181 (28.7%) patients with colon cancer; 91 of these patients (47 lung and 44 colon) were interviewed in detail. All patients had excellent performance status, and with the exception of pain location, there were no significant differences between the two tumor types. One-third of the patients had more than one discrete pain. Median pain duration was 4 weeks (range, less than 1 week-468 weeks), and average pain intensity was moderate. Approximately 90% of patients experienced pain more than 25% of the time. Pain interfered moderately or more with general activity and work in approximately half of the patients; more than half reported moderate or greater pain interference in sleep, mood, and enjoyment of life. Multiple regression analysis revealed that the daily frequency of pain, the intensity of the worst pain, the score on a mood scale, and the frequency of the worst pain accounted for 58.7% of the variance in average pain intensity. Likewise, 52.1% of the variance in a derived measure of pain interference in function was explained by the mood score, frequency of the worst pain, number of pains, and pain intensity.
Conclusions: These data indicate that pain is prevalent among well-functioning ambulatory patients and substantially compromises function in approximately half of the patients who experience it. Pain is a complex symptom; aspects other than intensity, such as frequency, strongly influence its effect.