The nine hole peg test as an outcome measure in progressive MS trials.

Background: The nine-hole peg test (NHPT) is the outcome measure with the least change in secondary and primary progressive MS (SPMS and PPMS) trials. The Standard NHPT is defined as the average of four measurements, two in each hand. Little is known about the performance of alternative NHPT scoring methods as longitudinal outcome measures in progressive MS. Non-ambulatory people with progressive MS are now generally excluded from clinical trials, and there is little information on longitudinal NHPT change in this patient group. In this investigation, we used patient-level data from two large randomized controlled trials in progressive MS to explore alternative NHPT scoring methods and NHPT change in non-ambulatory people with progressive MS.

Methods: We used patient-level data from the ASCEND (SPMS, n = 889) and PROMISE (PPMS, n = 943) clinical trials to compare significant change on the Standard NHPT with the alternatives dominant hand (DH), non-dominant hand (NDH), and either hand (EH) NHPT in ambulatory and non-ambulatory trial participants.

Results: The Standard NHPT changed slowly and showed few worsening events, as did the DH and NDH alternatives. Using the EH NHPT resulted in a substantial increase of worsening events. Non-ambulatory trial participants with PPMS experienced more NHPT worsening than ambulatory participants, especially when using the EH NHPT.

Conclusion: Using the EH NHPT yielded substantially more worsening events in people with progressive MS. Clinical trials in non-ambulatory people may be possible with the NHPT as the primary outcome measure. More research into the precision of these measures in this patient group is necessary.