A. Pathak1, S. Sharma2, A. Heinemann3, D. Ribeiro4, J.H. Abbott1
1University of Otago, Department of Surgical Sciences, Dunedin, New Zealand, 2Kathmandu University School of Medical Sciences, Department of Physiotherapy, Dhulikhel, Nepal, 3Northwestern University Feinberg School of Medicine, Department of Physical Medicine and Rehabilitation, Illinois, United States, 4University of Otago, School of Physiotherapy, Dunedin, New Zealand
Background: Individuals from diverse cultural backgrounds, including indigenous populations and immigrants, often struggle to comprehend patient-reported outcome measures (PROMs). Response options presented as a numeric rating scale create particular problems. The Patient-Specific Functional Scale (PSFS) is a widely used PROM used to assess function in many musculoskeletal conditions. The scale allows patients to nominate 3 to 5 tasks they have difficulty with and rate it on a 0-10 response format.
Purpose: We aimed to develop verbal response options for the PSFS for use in a low literacy country in South Asia — Nepal. We hypothesized that respondents would prefer a verbal rating scale for the PSFS to a numeric rating scale and have fewer errors. We also sought to discover if error rates were affected by age, education, language, or previous experience using numeric rating scales.
Methods: The study was conducted in two phases. First, we interviewed 42 individuals with musculoskeletal problems, chronic obstructive pulmonary disease, spinal cord injury, and stroke to understand how they describe varying levels of abilities. Then, we developed verbal response options for the PSFS. In Phase 2, we pre-tested the scales on 118 participants using the three-step test interview and paired comparison survey. We asked participants to indicate which response option they preferred and coded error rates qualitatively as a logical inconsistency, missing response, and/or multiple responses.
Results: Participants most commonly described their ability in terms of the quality (96%) and quantity of task performance (88%). We developed two sets of verbal responses for the PSFS and pre-tested them. Although respondents preferred the verbal (50%) over the numeric rating scale (12%), error rates were similar between numeric (34%) and verbal scales (31%, and 36%). Error rates were associated with previous use of a numeric scale, age, and years of education, with some groups displaying up to 80% error.
Conclusion(s): Although the PSFS is recommended for use in clinical practice, one in three respondents in Nepal are unable to accurately use it. The error rates are higher among those who are older, have less education, and no prior rating scale experience. Errors were not related to the type of response options. Patients may benefit from an interview format, explanatory prompts, fewer response options, and continued use of PROM along with observational measures.
Implications: The findings of our study question the utility of PROMs in low-literacy communities- can an outcome measure be considered truly patient-reported if participants are unable to understand scale instructions and use responses appropriately?
Funding, acknowledgements: Ms. Anupa Pathak is supported in her capacity as a Ph.D. student by the University of Otago Doctoral Scholarship.
Keywords: Patient-Specific Functional Scale, Assessment of function, Low-literacy
Topic: Professional practice: other
Did this work require ethics approval? Yes
Institution: Nepal Health Research Council (NHRC); University of Otago
Committee: NHRC Ethical Review Board; University of Otago Human Ethics Committee-Health (UOHEC)
Ethics number: NHRC-Reg. No. 791/2018; UOHEC-H18/146
All authors, affiliations and abstracts have been published as submitted.
