Disability insurance fills the income gap when catastrophe strikes, but it also provides a safety net when employees take time off work due to common health conditions, childbirth and life’s mishaps.

Understanding what causes disability-related workplace absences is one key to getting employees back to work, experts say. Working with insurance companies or third-party administrators, employers can use claims data to predict and prevent absences and devise strategies to help employees ease back into work.

“I’m definitely seeing a trend and an uptick in return-to-work and stay-at-work programs,” said Amy Blaisdell, an officer at Greensfelder, Hemker & Gale P.C. in St. Louis and leader of the firm’s labor and employment practice group.

Many of Ms. Blaisdell’s clients run self-funded disability plans that coordinate return-to-work and other absence management programs. “They’re very aware of the statistics that the longer somebody stays out of work, the less likely they are to come back to work,” she said.

Musculoskeletal conditions remain a leading cause of short- and long-term disability claims, observers point out.

“Because of the aging workforce, it’s become more prevalent,” noted Terri Rhodes, director of the Disability Management Employer Coalition in San Diego, whose member companies focus on enhancing workplace productivity through integrated disability and absence management strategies.

In 2014, Cigna Corp. analyzed 20 years of short-term disability claims data. The study revealed spikes in claims for obesity, skin cancer and herniated discs, conditions for which new treatments mean more employee absences.

One in four nonmaternity absences were musculoskeletal in nature, Cigna reported. Rounding out the top five causes of short-term disability are tendonitis/bursitis, arthritis, herniated discs and depression.

Cigna’s 20-year study excluded normal and complicated pregnancy to focus on illnesses and injury. In most years, though, normal pregnancy ranks second, behind musculoskeletal conditions as a driver of claims and absences. It accounts for 13%-14% of short-term disability claims and 12%-13% of absences, the insurer said.

On the long-term disability side, conditions affecting the muscles, bones, joints and connective tissues lead the list of new and ongoing claims, according to a 2014 claims review by the Council for Disability Awareness in Portland, Maine.

Other top causes of long-term disability include cancer and nervous system, cardiovascular and mental health disorders, CDA reports.

CDA President Carol Harnett often tells employers to look at ways to marry their health and disability data because it may reveal opportunities to reduce costs.

“If you can manage the disability, you have a really good shot of managing the health care,” she said.