Arthritis and Poverty: Chicken or Egg? Save

The development of arthritis is an underappreciated reason why individuals become impoverished -- a finding that was particularly pronounced for women, an Australian study found.

The hazard ratio for falling below the poverty line by 2012 among women who developed arthritis from 2007 to 2009 was 1.51 (95% CI 1.50-1.53), according to Emily J. Callender, PhD, and Deborah J. Schofield, PhD, of the University of Sydney.

And compared with men never diagnosed with arthritis during that time period, those with a diagnosis had a hazard ratio for poverty of 1.22 (95% CI 1.21-1.23), the researchers reported online in Arthritis & Rheumatology.

An international estimate for the prevalence of arthritis is one in eight among adults, and the number of affected persons is expected to rise by 50% in the next two decades.

Many studies have shown that participation in the labor force declines, along with incomes, among individuals with arthritis. However, little is known about the effects of arthritis on poverty status, including what is known as multidimensional poverty, which takes into account economic factors other than income.

Previous research has examined a cross-sectional relationship between poverty and arthritis, but no longitudinal data have thus far been available, so it has not been possible to determine which condition preceded the other.

To gain an increased appreciation of the risk of becoming impoverished following a diagnosis of arthritis, Callender and Schofield analyzed longitudinal data from the Household Income and Labor Dynamics in Australia (HILDA) survey, which has been conducted annually since 2001.

Income among HILDA participants was based on private income, such as wages, salary, and investments, and government-supported family or carer payments.

Income poverty was defined as income, adjusted for number and age of household members, below 50% of the Australian national median income.

Multidimensional poverty was assessed according to the Freedom Poverty Measure, which includes income, health, and education and is specific to the Australian population. "These three factors were selected by the creators of the Freedom Poverty Measure as they were seen to be key capabilities that influence an individual's ability to participate fully within all aspects of modern Australian society," the authors explained.

Health status was measured according to the Physical and Mental Component Summaries of the Short-Form-36 health survey, and poor health was defined as scores on these summaries below 75% for the average for age.

The analysis included participants who reported having been given a physician diagnosis of arthritis from 2007 to 2009 and who were not considered to be in income poverty in 2007.

Records were identified for 300 adults who developed arthritis during the study period through 2012, along with 3,943 who were free of arthritis. After weighting, this represented 454,100 Australians with arthritis and 6,084,600 without.

On univariate analysis, women were more likely to become impoverished than men (18% vs 16%,P0.0001), and the proportion falling into poverty increased with age (P0.0001) and remoteness of residence (P0.0001).

Fewer of those who were married or in a stable relationship were in poverty (14% vs 24%,P0.0001), as were fewer of those who owned their own homes (15% vs 22%,P0.0001).

On a sensitivity analysis that compared the likelihood of multidimensional poverty among individuals diagnosed with arthritis, the hazard ratio for women during the study period was 1.87 (95% CI 1.84-1.90) and for men, 1.29 (95% CI 1.29-1.30).

"Given the high prevalence of arthritis, which is expected to increase within the coming decades, arthritis should be seen as a major driver of national poverty rates," the researchers stated.

There has been increased interest among economic deprivation researchers in measuring the occurrence and effects of poverty over time to better understand risk factors. This study demonstrates that arthritis is a risk factor that needs addressing, according to the researchers.

"Given that multiple interventions have been shown to be effective in keeping people with arthritis in the labor force, more focus should be given to ensuring people with arthritis have access to these interventions," the researchers concluded.

Limitations of the study included a lack of information on the different types of arthritis and reliance on self-report of the diagnosis. In addition, the HILDA survey did not account for possible confounders such as comorbidities.

The authors reported no financial disclosures.

This story is brought to our readers by our friends at MedPage Today. It was originally published on September 9, 2015.