Functional capacity evaluation

Functional Capacity Evaluation Following Spinal Fusion Surgery

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

The aim of the study was to characterize outcomes of functional capacity evaluations (FCEs) amongst patients undergoing spinal fusion surgery.

SUMMARY OF BACKGROUND DATA

Injured workers often undergo an FCE upon reaching maximal medical improvement following surgery. To date, few studies have examined the results of FCEs following spinal fusion.

METHODS

Patients undergoing an FCE following a minimally invasive transforaminal lumbar interbody fusion (TLIF) or anterior cervical discectomy and fusion (ACDF) were retrospectively identified. Based upon the FCE report, each patient's job-related preoperative physical requirement and postoperative work capability was categorized as light, medium, or heavy. Patients were characterized as being able to meet their preoperative job requirement if their FCE-determined capability was greater than or equal to their preoperative job requirement. Patient characteristics were tested for association with meeting preoperative job requirement using bivariate and multivariate regression.

RESULTS

A total of 173 patients were identified: 71 (41.0%) and 102 (59.0%) underwent TLIF and ACDF, respectively. Of the 71 TLIF and 102 ACDF patients, 41 (58%) and 50 (49%) had light postoperative capabilities, 18 (25%) and 38 (37%) as medium, and 12 (17%) and 14 (14%) as heavy, respectively. Postoperatively, 26 (37%) of TLIF and 55 (54%) of ACDF patients were categorized as meeting their preoperative job requirement. Independent predictors of meeting preoperative job requirement following TLIF (P =0.002) and ACDF (P = 0.037) were lower preoperative job requirement, and younger age for ACDF (P < 0.001).

CONCLUSION

Only one in five patients undergoing spinal fusion surgery for occupational injuries is able to perform heavy-duty work postoperatively. Similarly, approximately half of patients are able to perform medium-duty work. Moreover, a majority of patients are unable to return to their preoperative occupational responsibilities. These findings can be used to council patients regarding their likelihood of meeting postoperative work capacity.

LEVEL OF EVIDENCE

3.

Construct validity of functional capacity evaluation lifting tests in construction workers on sick leave as a result of musculoskeletal disorders

OBJECTIVES

To assess the construct (discriminative and convergent) validity of 5 Ergo-Kit (EK) functional capacity evaluation (FCE) lifting tests in construction workers on sick leave as a result of musculoskeletal disorders (MSDs).

DESIGN

Cross sectional within-subject design.

SETTING

Occupational health service for the construction industry.

PARTICIPANTS

Male construction workers (N=72) on 6-week sick leave as a result of MSDs.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

After being assessed on 5 EK FCE lifting tests, participants were asked to complete the Von Korff questionnaire on pain intensity and disability as a result of MSDs and the instrument for disability risk assessing the risk for work disability. Discriminative validity was evaluated by comparing the results of the EK FCE lifting test scores between the 2 groups of participants based on the instrument for disability risk scores (high risk for work disability compared with low risk for work disability). Convergent validity was evaluated by assessing the associations between the results of the EK FCE lifting tests and Von Korff questionnaire self-reported pain intensity and disability as a result of MSDs.

RESULTS

The hypothesized differences between both instrument for disability risk groups on the 5 EK FCE lifting tests were found in the expected direction but were not statistically significant (1 test exhibited a trend). Pearson correlation coefficients showed a poor convergent validity between the scores of the Von Korff questionnaire and the EK FCE lifting tests (-.29< or =r< or =.05).

CONCLUSIONS

Poor construct validity of the 5 EK lifting tests was found: discriminative validity was not statistically established, and convergent validity with self-reported pain intensity and disability was poor.

Reliability and agreement of 5 Ergo-Kit functional capacity evaluation lifting tests in subjects with low back pain

OBJECTIVE

To assess interrater reliability and agreement of 5 Ergo-Kit functional capacity evaluation lifting tests in subjects with low back pain (LBP).

DESIGN

Within-subjects design, with 2 repeated measurements.

SETTING

Academic medical center in The Netherlands.

PARTICIPANTS

Twenty-four subjects (10 men, 14 women) with LBP.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Five Ergo-Kit lifting tests (2 isometric, 3 dynamic) were assessed on 2 occasions (t1, t2), by 2 different raters (R1, R2). The interval between the test sessions was 3 days. Interrater reliability level was expressed with the intraclass correlation coefficient (ICC), and the level of agreement between raters with the standard error (SE) of measurement.

RESULTS

ICCs means (reliability) of isometric and dynamic Ergo-Kit lifting tests ranged from .94 to .97, and SE of measurement values (agreement) ranged from 1.9 to 8.6 kg.

CONCLUSIONS

There was good reliability and agreement between raters of the isometric and dynamic Ergo-Kit lifting tests in subjects with LBP, which supports the use of these tests to assess functional lifting capacity.

Intra- and interrater reliability of the Ergo-Kit functional capacity evaluation method in adults without musculoskeletal complaints

OBJECTIVE

To evaluate the intra- and interrater reliability of tests from the Ergo-Kit (EK) functional capacity evaluation method in adults without musculoskeletal complaints.

DESIGN

Within-subjects design.

SETTING

Academic medical center in The Netherlands.

PARTICIPANTS

Twenty-seven subjects without musculoskeletal complaints (15 men, 12 women).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Seven EK tests (2 isometric, 3 dynamic lifting, 2 manipulation tests) were each assessed 3 times (over 4 days), twice by 1 rater (R1) and once by another rater (R2). Intrarater reliability was calculated using the EK test scores assessed by R1. Interrater reliability was calculated using the EK test scores assessed by both raters. Counterbalancing the rater order made possible the calculation of 2 interrater reliability levels (at time intervals of 4 and 8d). All reliability levels were expressed as intraclass correlation coefficients (ICCs).

RESULTS

Intrarater and interrater reliability (8-d time interval) was high (ICC, >.80) for the isometric lifting tests, moderate (ICC range, .50-.80) for the dynamic lifting tests, and low (ICC, <.50) for the manipulation tests. The interrater reliability of the isometric and dynamic lifting tests (4-d time interval) was high (ICC, >.80), and it was moderate (ICC range, .50-.80) for both manipulation tests.

CONCLUSIONS

The isometric and dynamic lifting tests of the EK have a moderate to high level of reliability; the manipulation tests have a low level of reliability.

Reliability and validity of Functional Capacity Evaluation methods: a systematic review with reference to Blankenship system, Ergos work simulator, Ergo-Kit and Isernhagen work system

OBJECTIVES

Functional Capacity Evaluation methods (FCE) claim to measure the functional physical ability of a person to perform work-related tasks. The purpose of the present study was to systematically review the literature on the reliability and validity of four FCEs: the Blankenship system (BS), the ERGOS work simulator (EWS), the Ergo-Kit (EK) and the Isernhagen work system (IWS).

METHODS

A systematic literature search was conducted in five databases (CINAHL, Medline, Embase, OSH-ROM and Picarta) using the following keywords and their synonyms: functional capacity evaluation, reliability and validity. The search strategy was performed for relevance in titles and abstracts, and the databases were limited to literature published between 1980 and April 2004. Two independent reviewers applied the inclusion criteria to select all relevant articles and evaluated the methodological quality of all included articles.

RESULTS

The search resulted in 77 potential relevant references but only 12 papers were identified for inclusion and assessed for their methodological quality. The interrater reliability and predictive validity of the IWS were evaluated as good while the procedure used in the intrarater reliability (test-retest) studies was not rigorous enough to allow any conclusion. The concurrent validity of the EWS and EK was not demonstrated while no study was found on their reliability. No study was found on the reliability and validity of the BS.

CONCLUSIONS

More rigorous studies are needed to demonstrate the reliability and the validity of FCE methods, especially the BS, EWS and EK.