A UK study has highlighted that significant numbers of patients with rheumatoid arthritis are not taking expensive drug treatments as prescribed.
The findings, published online in the journal Rheumatology, have prompted calls for clinicians to highlight the importance of the drugs to their patients.
Researchers from the University of Manchester found 40% of patients scored low in an adherence questionnaire at least once during their study.
“There is the assumption that people with rheumatoid arthritis regularly take their medication as prescribed, but our findings challenge this”
The study involved 392 rheumatoid arthritis patients who started taking the biological therapy adalimumab (Humira) during the period 2007-09.
Adalimumab is an anti-tumour necrosis factor drug that is given by subcutaneous injection. The usual dose is 40mg once every two weeks.
The researchers measured age, gender, psychological factors, disease activity, physical function and quality of life at baseline and at six, 12 and 18 months. Adherence was assessed at each follow-up using a patient self-completed questionnaire.
Low adherence was reported in 23% of patients, with 41% reporting low adherence during at least one of the measurement points, said the study authors.
They also found potential reasons to explain patient behaviour. For example, patients with a positive belief in the need for the drug were more likely to take their medication as were those with fewer concerns about potential side effects.
“Healthcare professionals and other information providers need to find more effective ways to inform their patients”
Other key factors included how patients viewed their illness. Those who appreciated the chronic nature of rheumatoid arthritis, had a better understanding of their disease and who felt they had high levels of professional or family support were also most likely to take their drugs as prescribed.
Senior author Professor Ian Bruce said: “This is one of the first studies to assess biological adherence in rheumatoid arthritis patients over time.
“In the era of new and effective high-cost drugs there is the assumption that people with rheumatoid arthritis regularly take their medication as prescribed, but our findings challenge this assumption,” he said.
“We have shown that health professionals should not assume that because biologics are effective and expensive that all patients will take these as prescribed,” noted Professor Bruce.
He added: “Importantly we have found a number of factors and patient beliefs that help us to understand why this is happening. If we can find ways to inform, support and empower our patients better, we may also be able to improve the regularity of taking these very effective medications in this potentially disabling condition.”
Belinda Wadsworth, head of health promotion at Arthritis Research UK, called on healthcare professionals to find “more effective ways” to inform their patients about the importance of taking drugs as prescribed.
People with rheumatoid arthritis need to have a “better understanding of why their medication is less effective if they don’t take it as directed”, she added.