Open Access

Objective: Functioning is an important outcome to measure in cohort studies. Clear and operational outcomes are needed to judge the quality of a cohort study. This paper outlines guiding principles for reporting functioning in cohort studies and addresses some outstanding issues. Design: Principles of how to standardize reporting of data from a cohort study on functioning, by deriving scores that are most useful for further statistical analysis and reporting, are outlined. The Swiss Spinal Cord Injury Cohort Study Community Survey serves as a case in point to provide a practical application of these principles. Methods and Results: Development of reporting scores must be conceptually coherent and metrically sound. The International Classification of Functioning, Disability and Health (ICF) can serve as the frame of reference for this, with its categories serving as reference units for reporting. To derive a score for further statistical analysis and reporting, items measuring a single latent trait must be invariant across groups. The Rasch measurement model is well suited to test these assumptions. Conclusion: Our approach is a valuable guide for researchers and clinicians, as it fosters comparability of data, strengthens the comprehensiveness of scope, and provides invariant, interval-scaled data for further statistical analyses of functioning.

Objective: To examine the relevance and completeness of the comprehensive International Classification of Functioning, Disability and Health (ICF) Core Sets for patients with rehabilitation needs in acute hospital care. Design: Multi-centre cohort study. Patients: A total of 391 patients (50.1% female, mean age 63.4 years) from 4 university hospitals in Austria, Germany and Switzerland and one Austrian general hospital. Methods: Data on functioning were collected using the respective comprehensive acute ICF Core Sets. Data were extracted from patients' medical record sheets and interviews with health professionals and patients. Results: Most of the categories of the comprehensive ICF Core Sets describing impairments, limitations or restrictions occurred in a considerable proportion of the study population. The most outstanding limitations and restrictions of the patients were problems with sleep and blood vessel functions, walking and moving and self-care. Thirty-eight aspects of functioning not previously covered by the comprehensive ICF Core Sets were ranked as relevant. Conclusion: Categories of the comprehensive ICF Core Sets for the acute hospital situation were confirmed. Some additional categories not covered by the Set in its present version emerged from the interviews, and should be considered for inclusion in a finalized version.

Background Contemporary casemix systems for health services need to ensure that payment rates adequately account for actual resource consumption based on patients’ needs for services. It has been argued that functioning information, as one important determinant of health service provision and resource use, should be taken into account when developing casemix systems. However, there has to date been little systematic collation of the evidence on the extent to which the addition of functioning information into existing casemix systems adds value to those systems with regard to the predictive power and resource variation explained by the groupings of these systems. Thus, the objective of this research was to examine the value of adding functioning information into casemix systems with respect to the prediction of resource use as measured by costs and length of stay. Methods A systematic literature review was performed. Peer-reviewed studies, published before May 2014 were retrieved from CINAHL, EconLit, Embase, JSTOR, PubMed and Sociological Abstracts using keywords related to functioning (‘Functioning’, ‘Functional status’, ‘Function*, ‘ICF’, ‘International Classification of Functioning, Disability and Health’, ‘Activities of Daily Living’ or ‘ADL’) and casemix systems (‘Casemix’, ‘case mix’, ‘Diagnosis Related Groups’, ‘Function Related Groups’, ‘Resource Utilization Groups’ or ‘AN-SNAP’). In addition, a hand search of reference lists of included articles was conducted. Information about study aims, design, country, setting, methods, outcome variables, study results, and information regarding the authors’ discussion of results, study limitations and implications was extracted. Results Ten included studies provided evidence demonstrating that adding functioning information into casemix systems improves predictive ability and fosters homogeneity in casemix groups with regard to costs and length of stay. Collection and integration of functioning information varied across studies. Results suggest that, in particular, DRG casemix systems can be improved in predicting resource use and capturing outcomes for frail elderly or severely functioning-impaired patients. Conclusion Further exploration of the value of adding functioning information into casemix systems is one promising approach to improve casemix systems ability to adequately capture the differences in patient’s needs for services and to better predict resource use.

Objective To demonstrate the influence and added value of a Standardized Assessment and Reporting System (StARS) upon the reporting of functioning outcomes for national rehabilitation quality reports. A StARS builds upon an ICF-based (International Classification of Functioning, Disability and Health) and interval-scaled common metric. Design Comparison of current ordinal-scaled Swiss national rehabilitation outcome reports including an expert-consensus-based transformation scale with StARS-based reports through descriptive statistical methods and content exploration of further development areas of the reports with relevant ICF Core Sets. Setting Swiss national public rehabilitation outcome quality reports on the clinic level. Participants A total of 29 Swiss rehabilitation clinics provided their quality report datasets including 18 047 patients. Interventions Neurological or musculoskeletal rehabilitation. Main outcome measures Functional Independence Measure™ or Extended Barthel Index. Results Outcomes reported with a StARS tended to be smaller but more precise than in the current ordinal-scaled reports, indicating an overestimation of achieved outcomes in the latter. The comparison of the common metric’s content with ICF Core Sets suggests to include ‘energy and drive functions’ or ‘maintaining a basic body position’ to enhance the content of functioning as an indicator. Conclusions A StARS supports the comparison of outcomes assessed with different measures on the same interval-scaled ICF-based common metric. Careful consideration is needed whether an ordinal-scaled or interval-scaled reporting system is applied as the magnitude and precision of reported outcomes is influenced. The StARS’ ICF basis brings an added value by informing further development of functioning as a relevant indicator for national outcome quality reports in rehabilitation.

Background: The Extended Barthel Index (EBI), consisting of the original Barthel Index plus 6 cognitive items, provides a tool to monitor patients’ outcomes in rehabilitation. Whether the EBI provides a unidimensional metric, thus can be reported as a valid sum-score, remains to be examined. Objective: To examine whether the EBI can be reported as unidimensional interval-scaled metric for neurological and musculoskeletal rehabilitation. Methods: Rasch analysis of a calibration sample of 800 cases from neurological or musculoskeletal rehabilitation in 2016 in Switzerland. Results: In the baseline analysis no fit to the Rasch Model was achieved. When accommodating local dependencies with a testlet approach satisfactory fit to the Rasch Model was achieved, and an interval scale transformation table was created. Conclusion: The results support the reporting of adapted EBI total scores for both rehabilitation groups by applying the interval scaled transformation table presented in this study.