Treatment with anti-TNF drugs and DMARDs is associated with clinically significant improvement measures of work disability such as presenteeism and productivity loss in patients with psoriatic arthritis.
Observational research from Britain indicates that patients who obtain proper treatment for psoriatic arthritis miss fewer days of work and get more done on the job.
Previous studies have consistently found that many people who develop the condition become dramatically less productive, both because they miss more days of work and because they accomplish less when they’re working. A significant number of them — estimates vary from 16% to 39% — do the least required to stay employed, a strategy known as presenteeism.
Drug trials have demonstrated that a number of compounds can ease the symptoms of psoriatic arthritis, but existing data provided little information about the effect such medications have on user output, so the authors of the new study recruited 400 untreated patients from 23 hospitals to investigate whether good care would make good workers.
Some patients used anti-tumor necrosis factor (anti-TNF) drugs while others began on disease-modifying antirheumatic drugs (DMARDs). Anti-TNF patients tended to have had the disease longer at baseline than those who started on DMARDs: mean 11years (interquartile range [IQR], 3.5-18.5 years) vs mean 5 years (IQR, 2-11 years). They also tended to have more tender joints (mean, 16; IQR ,11-25) and swollen joints (mean, 7; IQR, 5-12) compared to DMARD patients, who had an average of 11 tender joints(IQR, 5-20.25) and 5 swollen joints (IQR, 2-10). Other demographic and clinical measures were not significantly different. (This being an observational study, there was no placebo group.)
Neither type of treatment was associated with any significant increase or decrease in employment, but among the 236 patients who were employed at baseline, both medication classes were associated with increased output.
Presenteesim fell from 40% (IQR, 20-60) to 10% (IQR, 0-30) among anti-TNF patients (p=0.001), while productivity loss fell from 45% (IQR 26.2-67-8) to 10% (IQR, 0-30.0) in that group (p=0.001). Among patients in the DMARD group, presenteeism fell from 30% (IQR, 10-60) to 20% (IQR, 10-50), while productivity loss fell from 40% (IQR, 20-70) to 25% (IQR, 10-60) over the same time (p=0.001 for both observations).
“We observed a clinically significant improvement in presenteeism, productivity loss and disease activity after initiation of DMARD and anti-TNF treatment,” wrote the authors of the paper, who presented its findings at this year’s Congress of the European League Against Rheumatism. “Improvement in work disability and disease activity was greater and more rapid amongst those commenced on anti-TNF. This study suggests work disability is reversible in the real world setting.”
The study followed patients for 24 weeks, but presenteeism began to decline in both treatment groups just 2 weeks after initial treatment and it continued to decline, though at a slower rate, until the end of the study period.
The study team speculated that the anti-TNF treatment saw greater improvements in output because its members, on average, responded better to treatment than those in the DMARD group. Mean DAPSA scores fell from 53 (IQR, 38.3-68.4) to 14 (IQR, 6.9-37.4) in the anti-TNF group (p=.001), which is defined as a good response using established cut points. Mean DAPSA scores in the DMARD group, however, only dropped from 39 (IQR, 27.9-58.4) to 30 (IQR, 18.4-38.5) in the DMARD group (p=.001), which is defined as a poor response.