Other Measures Outrace DASH in Assessing Hand Disability

The most popular measure of upper extremity physical function, the Disability of the Arm, Shoulder and Hand (DASH) instrument, may not actually be best, to judge from two studies announced this week at the American Academy of Orthopaedic Surgeons meeting in New Orleans.

Andrew Tyser MD and a group from the University of Utah Health Sciences Center tested DASH against a new instrument created by an NIH-sponsored effort, and found it to be considerably slower. It took 145 patients in a hand surgeon's clinic an average of 4.5 minutes to complete the DASH but only 48 seconds to dash through the four questions of the PF-CAT (Physical Function Computerized Adaptive Test).

While the instruments were comparably reliable, the DASH was also less informative due to ceiling effects -- too many responses clustered near the top of functionality, which tends to reduce its discrimination among less severely affected patients.

PF-CAT was created as part of the government's PROMIS (Patient-Reported Outcomes Measurement Information System) effort. The next step, the Utah researchers feel, should be to create a version customized for upper extremities.

The DASH also may not be as good a measure of function as simply asking patients how much the hand hurts, at least if what hurts is the thumb. James Lin MD of Columbia University Medical Center in New York reported on results from a prospective multicenter registry study of patients with carpometacarpal arthritis being conducted there, at St. Luke's-Presbyterian in New York, Vanderbilt, and the Mayo Clinic.

The team asked 142 patients, 56 of whom had pain in both thumbs, to complete the DASH in addition to  measuring range of motion for 7 hand maneuvers as well as pinch strength and grip strength. They also asked patients to report their pain on a visual analogue scale (VAS).

The only significant predictor of the DASH score, they found, was pain -- and that was highly significant. Their conclusion? In this form of arthritis, either objective measures of functional limitation may not be important to the perceived disability, or DASH may simply be insensitive.

In either case, they conclude, pain with activity is the measure that merits most attention in these patients.