Predictive validity of a customized functional capacity evaluation in patients with musculoskeletal disorders

User-Centred Design to Inform Requirements for a Remotely Administered Hybrid Functional Test (RAHFT) Protocol

PURPOSE

Functional testing is important to inform return-to-work (RTW), but new paradigms are needed to increase access and availability of testing. Our purpose was to deploy a user centred design approach to collect, describe, and interpret end-user feedback (clinicians and patients) to inform functional requirements for a remotely administered hybrid functional test (RAHFT) protocol.

METHODS

Twenty participants (10 clinicians and 10 patients) were interviewed about existing in-person functional testing and about perceptions of prospective remotely administered functional testing protocols. Interview data were synthesized, where findings informed a focus group with functional testing clinician experts to identify functional design requirements for a RAHFT protocol.

RESULTS

Patients agreed that access to equipment and technology, safety, and personal connections were important requirements for a functional testing protocol. Expert clinicians emphasized that a RAHFT should provide valid information to inform treatment planning and RTW outcome decisions, inclusive of opportunities to capture subjective and performance-based information.

CONCLUSIONS

RAHFT protocols can play an important role towards early and safe RTW. RAHFT protocols will increase availability and improve access for workers that cannot easily attend a clinic for in-person testing. Findings from this study provide functional requirements that should be considered when designing RAHFT protocols.

Tele-Assessment of Functional Capacity: Validity, Intra- and Inter-rater Reliability

BACKGROUND

Functional capacity evaluation is a standardized tool that assesses work-related skills. Although there are different test batteries, the most frequently used one is Work Well Systems. This study aims to determine the validity and inter- and intra-rater reliability of remote implementation of functional capacity tests (repetitive reaching, lifting object overhead, and working overhead) in asymptomatic individuals.

METHODS

A total of 51 asymptomatic individuals were included in the study. Participants completed all tests both face-to-face and remotely. Remote assessment videos were rewatched by the same researcher and different researchers for intra- and inter-rater reliability. All processes were scored by two independent researchers.

RESULTS

Remotely performing repetitive reaching (intraclass correlation coefficient [ICC]: 0.85-0.92, p < .001), lifting object overhead (ICC: 0.98, p < .001), and working overhead (ICC: 0.88 p < .001) tests are valid and reliable.

DISCUSSION

Repetitive reaching, lifting an object overhead, and sustained overhead work tests in the Work Well Systems-Functional Capacity Evaluation test battery can be performed remotely through videoconferencing. Remotely evaluating these tests, which are especially important in work-related situations, may be important in pandemic conditions and hybrid working conitions.

Matching Perceived Physical Capacity and Work Demands: A New Classification of the Modified Spinal Function Sort (M-SFS)

Purpose The aims of this study were (1) to develop a new classification for the scores of the Modified Spinal Function Sort (M-SFS) which is related to the level of physical work demands and (2) to test the predictive value of the M-SFS classification. Methods The classification was carried out in 194 subjects with musculoskeletal disorders (MSD) attending a work-related medical rehabilitation from four rehabilitation centers. External criterion was a Functional Capacity Evaluation (FCE)-based work capacity estimation according to the classification used in Germany ("REFA") which differentiates between light, light to medium, medium and heavy work. The optimal cut-offs for the M-SFS were allocated using the Youden index. Logistic regression models were calculated based on 147 subjects who participated in the follow-up survey to evaluate the predictive validity of the M-SFS classification with regard to sustainable return to work (RTW; employment at the 3-month follow-up combined with a low level of sick leave). Results Cut-offs for M-SFS scores were 44 (light work), 54 (light to medium work), 62 (medium work) and 73 (heavy work). A match between the M-SFS category and the level of physical work demands was associated with a more than threefold higher RTW chance compared to subjects with a negative discrepancy. In case the M-SFS category was above the physical demand level the RTW-chance was more than 13-fold higher. Conclusions M-SFS scores can be classified into four levels of physical work demands. If the perceived work capacity matches or exceeds the level of physical work demands patients with MSD have a substantially higher probability to return to work after rehabilitation. More studies are needed to confirm or reject our findings and overcome some of the weaknesses of this study.

Do patient characteristics affect the predictive validity of Functional Capacity Evaluations?

Purpose

The aim of this study was to identify patient-related characteristics that affect the predictive validity of the FCE assessment ELA.

Methods

A prospective multicenter study was conducted on 303 patients with musculoskeletal disorders (MSD) recruited from eleven rehabilitation centers. The ELA-based estimation of the participants' ability to cope with physical work demands was considered valid if RTW was paired with a positive ELA outcome (≥ moderate) as well as if non-RTW was accompanied by a negative ELA outcome (rather or very poor). In the remaining cases, the ELA result was judged as non-valid. To reduce the risk of false conclusions, the rating was performed inversely in participants that (1) reported severe limitations regarding their productivity at work, (2) attributed RTW to a change in job resp. a reduction of their physical work demands and in those that (3) attributed non-RTW to non-physical reintegration barriers only. Using questionnaires, 28 patient-related characteristics were collected. Logistic regression models were calculated to identify characteristics that affected the predictive validity of ELA.

Results

ELA was considered valid in 208 of 303 (69%) participants. A moderate and strong pain-related disability at work were associated with a 0.15-fold (95% confidence interval (95% CI) 0.05–0.46), respectively, 0.19-fold (95% CI 0.05–0.72) chance for a valid outcome. In addition, a negative influence was found in participants that reported psychosocial distress (odds ratio (OR) 0.35; 95% CI 0.15–0.82), a native language different from the national language (OR 0.16; 95% CI 0.05–0.56) as well as in those that expected to return to work, but not within one month (OR 0.17; 95% CI 0.06–0.46). Further variables—including age, employment status, fear-avoidance beliefs and the level of physical work demands—did not affect the predictive validity of ELA.

Conclusions

The results suggest that the predictive validity of ELA is primarily limited by patients that report a moderate or strong pain-related disability at work, psychosocial distress as well as the expectation to return to work, but not within one month. Furthermore, a negative influence can be assumed for language barriers.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00420-021-01807-7.