Patient-reported outcomes in rehabilitation research: instruments and current developments in Germany

Development of Rasch-based short screenings for the assessment of treatment motivation in patients with cardiovascular diseases

Purpose: The aim of the study was to develop unidimensional test-fair and economic short screenings to assess treatment motivation in patients with cardiovascular diseases using the Rasch analysis.Materials and methods: After pretesting for relevance and comprehension, a pool of 132 items on treatment motivation was completed by a sample consisting of 1168 patients with cardiovascular diseases recruited in two German cardiological rehabilitation centers. Confirmatory factor analyses and the Rasch analyses were conducted.Results: The confirmatory factor analyses confirmed a three-factor structure of the treatment motivation construct with task self-efficacy, outcome expectancies and intention as factors. Using the Rasch analysis for each of the three factors and removing items with misfit, differential item functioning and local response dependency reduced the initial item pool to the three short screenings. The short screenings fit to the Rasch model with a root mean square error of approximation (RMSEA = 0.021 (task self-efficacy; seven items); RMSEA = 0.024 (outcome expectancies; 12 items), RMSEA = 0.027 (intention; nine items). Person-separation reliability was 0.81, 0.82, and 0.73. Unidimensionality could be verified.Conclusions: The calibrated, unidimensional short screenings provide a psychometrically sound option for an initial- and follow-up assessment of treatment motivation in rehabilitation patients with cardiovascular diseases. Further testing in other cardiovascular diseases populations is needed to increase generalizability.Implications for rehabilitationNew short screenings for the assessment of treatment motivation: task self-efficacy, outcome expectancies, intention in rehabilitation patients with cardiovascular diseases are available.Treatment motivation short screenings_{self-efficacy/outcome expectancies/intention} consist of seven items (treatment motivation short screening_{self-efficacy}), 12 items (treatment motivation short screening_{outcome expectancies}), nine items (treatment motivation short screening_intention) and are therefore especially timesaving.The short screenings demonstrate good psychometric properties, cover a wide spectrum of task self-efficacy, outcome expectancies and intention, and are free of local dependencies and of differential item functioning regarding to gender, age and cardiovascular diagnoses.Using a Rasch based unidimensional short screening is a test-fair and economic method to assess patients' treatment motivation, which might help to improve rehabilitation health care tailored to patients' needs.

Choosing the right rehabilitation setting after herniated disc surgery: Motives, motivations and expectations from the patients' perspective

Objectives

This study aims to investigate (1) motives, motivations and expectations regarding the choice for a specific rehabilitation setting after herniated disc surgery and (2) how rehabilitation-related motivations and expectations are associated with rehabilitation outcome (ability to work, health-related quality of life and satisfaction with rehabilitation) three months after disc surgery.

Methods

The longitudinal cohort study refers to 452 disc surgery patients participating in a subsequent rehabilitation. Baseline interviews took part during acute hospital stay (pre-rehabilitation), follow-up interviews three months later (post-rehabilitation). Binary logistic regression and multiple linear regression analyses were applied.

Results

(1) Motives, motivations and expectations: Inpatient rehabilitation (IPR) patients stated “less effort/stress” (40.9%), more “relaxation and recreation” (39.1%) and greater “intensity of care and treatment” (37.0%) regarding their setting preference, whereas outpatient rehabilitation (OPR) patients indicated “family reasons” (45.3%), the wish for “staying in familiar environment” (35.9%) as well as “job-related reasons” (11.7%) as most relevant. IPR patients showed significantly higher motivation/expectation scores regarding regeneration (p < .001), health (p < .05), coping (p < .001), retirement/job (p < .01), psychological burden (p < .05) and physical burden (p < .001) compared to OPR patients. (2) Associations with rehabilitation outcome: Besides other factors (e.g. age, gender and educational level) rehabilitation-related motivations/expectations were significantly associated with rehabilitation outcome measures. For example, patients with less motivations/expectations to achieve improvements regarding “physical burden” showed a better health-related quality of life (p < .01) three months after disc surgery. Less motivations/expectations to achieve improvements regarding “psychological burden” was linked to a better mental health status (p < .001) and a greater satisfaction with rehabilitation (OR = .806; p < .05).

Conclusion

Rehabilitation-related motivations and expectations differed substantially between IPR and OPR patients before rehabilitation and were significantly associated with rehabilitation outcome. Taking motivational and expectation-related aspects into account may help to improve allocation procedures for different rehabilitation settings and may improve rehabilitation success.

Agreement between pre-post measures of change and transition ratings as well as then-tests

Background

Different approaches have been developed for measuring change. Direct measurement of change (transition ratings) requires asking a patient directly about his judgment about the change he has experienced (reported change). With indirect measures of change, the patients’ status is assessed at different time points and differences between them are calculated (measured change). When using the quasi-indirect approach (‘then-test’), patients are asked after an intervention to rate their statuses both before the intervention as well as at the time of the enquiry. Associations previous studies have found between the different approaches might be biased because transition ratings are generally assessed using a single, general item, while indirect measures of change are generally based on multi-item scales. We aimed to quantify the agreement between indirect and direct as well as indirect and quasi-indirect measures of change while using multi-item scales exclusively. We explored possible reasons for non-agreement (present-state bias, recall bias).

Methods

We re-analysed a data set originally collected to investigate the prognostic validity of different approaches of change measurements. Patients from a 3-week inpatient rehabilitation programme for either cardiac or musculoskeletal disorders filled in health-status questionnaires (which included scales for sleep function, physical function, and somatisation) both at admission and at discharge. The patients were then randomised to receive either an additional transition-rating or then-test questionnaire at discharge.

Results

Out of 426 patients, 395 (92.7%) completed all questionnaires. Correlation coefficients between indirect and quasi-indirect measures of change ranged from r = .60 to r = .71, compared to r = .37 to r = .48 between indirect and direct measures of change. Correlation coefficients between pre-test and retrospective pre-test (then-test) results ranged from r = .69 to r = .82, indicating a low level of recall bias. Pre-test variation accounted for a substantial amount of variance in transition ratings in addition to the post-test scores, indicating a low level of present-state bias.

Conclusions

Indirect and quasi-indirect measurements of change yielded comparable results indicating that recall bias does not necessarily affect quasi-indirect measurement of change. Quasi-indirect measurement might serve as a substitute for pre-post measurement under conditions still to be specified. Transition ratings reflect different aspects of change than indirect and quasi-indirect methods do, but are not necessarily biased by patients’ present states.

Development of a screening tool predicting the transition from acute to chronic low back pain for patients in a GP setting: protocol of a multinational prospective cohort study

BACKGROUND

Low back pain (LBP) is by far the most prevalent and costly musculoskeletal problem in our society today. Following the recommendations of the Multinational Musculoskeletal Inception Cohort Study (MMICS) Statement, our study aims to define outcome assessment tools for patients with acute LBP and the time point at which chronic LBP becomes manifest and to identify patient characteristics which increase the risk of chronicity.

METHODS

Patients with acute LBP will be recruited from clinics of general practitioners (GPs) in New Zealand (NZ) and Switzerland (CH). They will be assessed by postal survey at baseline and at 3, 6, 12 weeks and 6 months follow-up. Primary outcome will be disability as measured by the Oswestry Disability Index (ODI); key secondary endpoints will be general health as measured by the acute SF-12 and pain as measured on the Visual Analogue Scale (VAS). A subgroup analysis of different assessment instruments and baseline characteristics will be performed using multiple linear regression models. This study aims to examine: 1. Which biomedical, psychological, social, and occupational outcome assessment tools are identifiers for the transition from acute to chronic LBP and at which time point this transition becomes manifest. 2. Which psychosocial and occupational baseline characteristics like work status and period of work absenteeism influence the course from acute to chronic LBP. 3. Differences in outcome assessment tools and baseline characteristics of patients in NZ compared with CH.

DISCUSSION

This study will develop a screening tool for patients with acute LBP to be used in GP clinics to access the risk of developing chronic LBP. In addition, biomedical, psychological, social, and occupational patient characteristics which influence the course from acute to chronic LBP will be identified. Furthermore, an appropriate time point for follow-ups will be given to detect this transition. The generalizability of our findings will be enhanced by the international perspective of this study.

TRIAL REGISTRATION

[Clinical Trial Registration Number, ACTRN12608000520336].

Differences across health care systems in outcome and cost-utility of surgical and conservative treatment of chronic low back pain: a study protocol

Background

There is little evidence on differences across health care systems in choice and outcome of the treatment of chronic low back pain (CLBP) with spinal surgery and conservative treatment as the main options. At least six randomised controlled trials comparing these two options have been performed; they show conflicting results without clear-cut evidence for superior effectiveness of any of the evaluated interventions and could not address whether treatment effect varied across patient subgroups. Cost-utility analyses display inconsistent results when comparing surgical and conservative treatment of CLBP. Due to its higher feasibility, we chose to conduct a prospective observational cohort study.

Methods

This study aims to examine if

1. Differences across health care systems result in different treatment outcomes of surgical and conservative treatment of CLBP

2. Patient characteristics (work-related, psychological factors, etc.) and co-interventions (physiotherapy, cognitive behavioural therapy, return-to-work programs, etc.) modify the outcome of treatment for CLBP

3. Cost-utility in terms of quality-adjusted life years differs between surgical and conservative treatment of CLBP.

This study will recruit 1000 patients from orthopaedic spine units, rehabilitation centres, and pain clinics in Switzerland and New Zealand. Effectiveness will be measured by the Oswestry Disability Index (ODI) at baseline and after six months. The change in ODI will be the primary endpoint of this study.

Multiple linear regression models will be used, with the change in ODI from baseline to six months as the dependent variable and the type of health care system, type of treatment, patient characteristics, and co-interventions as independent variables. Interactions will be incorporated between type of treatment and different co-interventions and patient characteristics. Cost-utility will be measured with an index based on EQol-5D in combination with cost data.

Conclusion

This study will provide evidence if differences across health care systems in the outcome of treatment of CLBP exist. It will classify patients with CLBP into different clinical subgroups and help to identify specific target groups who might benefit from specific surgical or conservative interventions. Furthermore, cost-utility differences will be identified for different groups of patients with CLBP. Main results of this study should be replicated in future studies on CLBP.