Comments regarding “Mobility Analysis of AmpuTees (MAAT I): Quality of life and satisfaction are strongly related to mobility for patients with a lower limb prosthesis” by Wurdeman et al.

Dear Editor in Chief

The authors of the recently published level III retrospective case series entitled “Mobility Analysis of AmpuTees (MAAT I): Quality of life and satisfaction are strongly related to mobility for patients with a lower limb prosthesis” are to be commended for advancing outcome collection and reporting in lower limb prosthetics. ¹ The strong positive correlation between mobility and both quality of life and general satisfaction is unsurprising.

Using goal attainment scaling (GAS) researchers previously determined that mobility is the primary concern of persons with a lower limb amputation. ² Rising and sitting down as well as climbing stairs can be particularly challenging. Since mobility is of great concern for the amputee and important to recovery, the accurate measurement of mobility becomes paramount in the rehabilitation process. Mobility measurement can be performed through questionnaires (perception), physical test (capacity), or activity monitors (performance). ³ Unfortunately, agreement between perception, capacity, and performance is poor.^4,5

Measurement error with self-report data comes from three sources, namely, the method or instrument of collection, contextual factors, and the respondents themselves. Self-report response bias, such as social desirability, acquiescence, leniency or harshness, critical event and recency, halo effect, extreme response style and mid-point style, has the potential to impact self-report data. Specifically, the PLUS-M (Prosthetic Limb Users Survey of Mobility) demonstrated only a moderate positive relationship with Amputee Mobility Predictor scores (p = .54, p < .001) and a moderate negative relationship with Timed “Up and Go” results (p = .56, p < .001), both physical capacity tests. The PLUS-M did demonstrate strong positive relationships with other self-report tools such as the Prosthetic Evaluation Questionnaire (p = .78, p < .001), ABC (Activities-Specific Balance Confidence) Scale (p = .81, p < .001), and PROMIS-PF T scores (p = .81, p < .001). ⁶

Since the questionnaires of this study were administered during a clinic visit, perhaps, further research would have better applicability if factors like quality of life and general satisfaction were compared to physical capacity examination or activity performance monitors. Simply put, as long as the patient is present, why not take advantage of the opportunity to perform a physical capacity test and observe and document rising and sitting down as well as stair climbing and descending with and without a handrail?

Respectfully submitted,

James P Reichmann1322 Garrick WayMarietta, GA 30068, USA