Quality of Life, Work Appear to Improve for Patients Taking Humira in China
Treatment with Humira (adalimumab) over six months significantly reduced symptoms and improved physical function, quality of life, and work productivity in ankylosing spondylitis (AS) patients, a Chinese study finds.
The study, “Cost of Illness, Quality of Life, and Work Outcomes in Active Ankylosing Spondylitis Patients Treated With Adalimumab in China,” was published in the journal Frontiers in Public Health.
AS is characterized by inflammation in the joints of the spine, causing lower back pain and stiffness, as well as impaired physical function and quality of life. The disease may also affect the ability to maintain regular employment. A past study in China found that 10.5% of AS patients surveyed were not working, and those working reported an average 17% decrease in productivity related to the disease.
Humira is an antibody that blocks TNF-alpha, a pro-inflammatory molecule highly produced in AS patients. The medication has been shown to reduce disease signs and symptoms, and improve work productivity.
In the new study, researchers set out to estimate the impact of Humira treatment on the cost of illness, work productivity, quality of life, and physical functioning in patients with active AS in China.
A total of 91 patients were included in the study from January 2017 to June 2018. They had suboptimal control of their disease — defined as a Bath Ankylosing Spondylitis Disease Activity Index score of 4 or higher. The average age of the participants was 30.6 years, 87.8% were male, and mean disease duration was 10 years. All patients received 40 mg of Humira every two weeks for a total of 24 weeks (six months).
Mean disease activity among the participants was 5.31 and their functional limitation was 4.23 on a 1–10 scale, where 10 is the most severe. Mean activity impairment due to ill-health was 48.57%.
The mean annual cost of illness per patient was $37,581.41. Direct costs accounted for 84.6% of the total, with the majority (73.7%) going to Humira treatment. Indirect costs included productivity loss, which accounted for 8.11% of total costs and 52.7% of indirect costs, as well as sick leave.
After six months on Humira, both disease activity and functional impairment were reduced. Quality of life was significantly improved compared to baseline (study start), both when using an AS-specific measure and when analyzing results of a tool that includes mobility, self-care, usual activities, pain/discomfort, anxiety/depression, and general health status.
At baseline, 71 patients (78%) were employed with average work absenteeism of 10.22%, presenteeism (present but not fully functioning) of 43.86%, and work productivity loss of 47.92%. Absenteeism, presenteeism, and work productivity loss were all reduced after six months of treatment.
Longer disease duration, higher functional impairment, and low AS-related quality of life were associated with poor functioning at work. Disease duration was also linked to work absenteeism. In turn, work productivity loss correlated with age, education level, functional impairment, and AS-related QoL.
“Long disease duration, poor physical function and low quality of life were found to be related to poor work outcomes,” the investigators wrote. “Improvement of the social insurance system, early diagnosis and patient education would help to alleviate work disability in AS patients.”
According to the team, limitations of the study include the relatively small sample size, the inclusion of only patients with high disease activity, and the relatively short follow-up time that prevented evaluation of any long-term effects of Humira treatment.