Prevalence and associated factors for falls in women with established inflammatory polyarthritis

To determine the one-year period prevalence and factors associated with falls in a community based cohort of women with established inflammatory polyarthritis (IP).

The Norfolk Arthritis Register is a primary-care based inception cohort of subjects with IP aged 16 years and over. At the 10-year visit, subjects completed the Health Assessment Questionnaire (HAQ) and were examined for both active and inactive joint involvement. A subset of subjects was invited to complete a questionnaire about falls in the previous 12 months and questions about putative risk factors for falls. Logistic regression was used to determine whether there was any association between falls in the previous year and both putative disease and non-disease related risk factors.

Of the 316 women (mean age 59 yrs) who completed the falls questionnaire, 34% reported a fall in the previous year. Falls were more frequent in those over age 75 years, although there was no significant linear increase in risk with age. Swollen joint count [per 10 joints, odds ratio (OR) 1.7; 95% confidence interval (CI) 1.0, 2.8] and increasing visual analog scale pain score (per 10 mm, OR 1.1; 95% CI 1.0, 1.2) were associated with an increased risk of falls. Those who fell had higher overall HAQ scores (OR 1.7; 95% CI 1.3, 2.3) as well as higher scores for all of the individual domains of the HAQ (OR 1.7 to 2.2). Similarly, low levels of outdoor physical activity (OR 3.3; 95% CI 1.7, 6.5), impaired vision (OR 2.7; 95% CI 1.2, 6.3), and impaired general health (OR 2.9; 95% CI 1.7, 4.8) were associated with an increased risk of falls. In a multivariate model, HAQ score, low levels of physical activity, impaired vision, and impaired general health were independently linked with falls. Sixty-one percent of subjects with 3 of these risk factors had reported a fall in the previous year.

In this inception cohort of women with longstanding IP, one in 3 reported falling in the previous year. Using a simple measure, a group that had particularly high risk can be identified.