How do Blue-Collar Jobs Influence Work Disability in Patients with Psoriatic Arthritis?

Julia-Tatjana Maul, MD

Credit: University of Zurich

Although treatment response among patients with psoriatic arthritis (PsA) was seemingly unaffected by occupation type, patients with more physically demanding, blue-collar jobs had increased rates of work disability compared with white-collar occupations.

Previous research has revealed a link between a PsA diagnosis and reduced work productivity, with up to 40% of patients requiring work disability due to their disease, particularly for those with high disease activity.

“Occupations can be broadly categorized as either physically demanding (i.e., blue-collar workers) or less demanding (i.e., white-collar workers),” wrote a team of investigators including Julia-Tatjana Maul, MD, senior physician in the Department of Dermatology and Venerology at the University of Zurich, Switzerland. “Because blue-collar workers often face higher levels of biomechanical stress on their joints and entheses, this could trigger or worsen inflammation in these areas, leading to higher disease activity or poorer response to medication among PsA patients who work in physically demanding occupations.”

To investigate the role biomechanical stress may have on this patient population, investigators evaluated disease activity, drug response, treatment retention rates and work disability among those who performed manual labor and those with sedentary occupations. Patients were recruited from the Swiss Clinical Quality Management in Rheumatic Diseases (SCQM) registry and assessed at treatment initiation. Eligible patients were aged ≥ 18 years, were treated with a biologic or targeted synthetic disease modifying anti-rheumatic drug (b/tsDMARDs) and had available physical examination data at treatment initiation and follow-up.

Investigators determined whether a patient could be classified as blue-collar or white-collar using information about a patient’s work sector—such as “Service,” “Transportation,” “Agriculture,” “Manufacturing” and “Housekeeper”—as well as the physical stress level at work (high vs low).

In total, 564 patients were identified, with 71% placed in the white-collar group and 29% in the blue-collar group. Patients under the blue-collar umbrella were mostly male (79.8% vs 41.7%) and more work disabled at baseline compared with the white-collar cohort (84.0% vs 27.9%). These patients were also more likely to quit their jobs due to disease burden (19.1% vs 7.8%).

A longitudinal analysis assessed 174 treatment courses of 165 patients to determine the achievement of remission using the Disease Activity Score 28 using C-reactive protein (DAS28-CRP). At the 1-year mark, remission rates did not appear to be significantly influenced by occupation. However, lower rates were linked to female sex and a body mass index (BMI) > 30 kg/m2.

Although one analysis showed blue-collar workers had a longer treatment retention, the adjusted Cox regression analysis did not confirm these results.

Researchers emphasized that work disability is a complicated issue and can be impacted by multiple factors, such as physical health, socioeconomic status and disease burden. The repetitive nature of jobs with higher levels of physical stress, for example, may lead to higher disability because of musculoskeletal disorders, injuries and even early osteoarthritis. Patients with blue-collar occupations may also experience greater socioeconomic challenges, which could impact their ability to manage their PsA while remaining employed.

The observational nature of the study was considered a limitation, as it was difficult for investigators to link physical workload to disease burden. Additionally, it is possible patients weren’t correctly categorized as either blue-collar or white-collar. Even within these groups, workload may vary considerably, potentially further altering results.

“Further research is needed to fully understand the impact of physical workload on disease burden and to develop effective interventions for preventing long-term work disability among PsA patients,” investigators concluded.