Pain in patients with multiple sclerosis: a population-based study

Abstract

Background: Pain is an important symptom in patients with multiple sclerosis (MS). The estimated pain prevalence varies between 30% and 90%. To our knowledge, previous studies do not include a whole population sample of patients with MS.

Objective: To assess pain prevalence and its clinical characteristics and impact on daily life in a population sample of MS patients and in a reference group.

Design: Postal survey.

Setting: Aarhus County, Denmark.

Participants: The population of patients with definite MS in Aarhus County (n = 771) and a sex- and age-stratified reference group from the general population (n = 769).

Main outcome measures: Pain prevalence, intensity, and treatment requirement; and the impact of pain on daily life.

Results: Response rates for MS patients and reference subjects were 81.3% and 63.3%, respectively. Pain in the month preceding assessment occurred in 79.4% of MS patients and in 74.7% of reference subjects (prevalence proportion ratio, 1.06; 95% confidence interval, 0.99-1.13). Patients with MS had a higher pain intensity ("when pain is at its least" median visual analog scale score, 20.0 vs 11.0 mm [P<.01];and "when pain is at its worst" median visual analog scale score, 68.0 vs 55.0 mm [P<.01]). Daily intake of analgesics occurred in 24.4% of MS patients and 9.0% of reference subjects (prevalence proportion ratio, 2.7; 95% confidence interval, 2.0-3.6). Patients with MS more often reported that pain interfered with daily life "most of the time" or "all the time."

Conclusions: The frequency of reported pain in MS patients was not higher than in the background population. However, pain intensity, the need for analgesic treatment, and the impact of pain on daily life were higher in MS patients.