Reliability and validity of the de Morton Mobility Index in individuals with sub-acute stroke

Validation of the de Morton mobility index (DEMMI) among acute stroke patients aged ≥65 years: a register study

PURPOSE

To validate the de Morton Mobility Index (DEMMI) in older (≥65 years) patients with acute stroke in a hospital setting within the first week after stroke onset.

MATERIALS AND METHODS

In the Danish National Database of Geriatrics, we identified 4,176 patients with acute stroke (≥65 years). Floor and ceiling effects of DEMMI were investigated. Furthermore, convergent validity was investigated by correlations between DEMMI and the Barthel Index using Spearman's rho. Known-groups validity was tested by comparing DEMMI scores for different groups (with/without dementia, depression, comorbidity, and walking aids), and unidimensionality of DEMMI was evaluated by Mokken scale analysis.

RESULTS

A floor effect was identified with 22.1% of the patients scoring 0 on DEMMI on admission. Both convergent and known-groups validity were confirmed for DEMMI. Patients who were bedbound had a lower DEMMI score (median [IQR]: 0 [0;0]) than patients without any walking aid (median [IQR]: 62 [33;74]). Furthermore, Mokken scale analysis identified unidimensionality with overall fit to the model (Loevinger H 0.88 (p < 0.0001)).

CONCLUSION

DEMMI is a valid instrument for use in patients with acute stroke (≥65 years) in a hospital setting within the first week after stroke onset.

The impact of a coronavirus disease 2019 pandemic-related interruption of regular physical rehabilitation on functional abilities in a patient with two chronic neurological diseases: a case report

Background

Regular outpatient rehabilitation is prescribed for many patients with chronic neurological disorders, such as Parkinson’s disease or multiple sclerosis, to constantly support patients and their proxies in disease management. Due to the coronavirus disease 2019 pandemic, federal institutions and governments worldwide have directed local or nationwide lockdowns. During these times, the provision of regular outpatient rehabilitation service is drastically limited, making it actually impossible for community-dwelling patients with neurological disorders to receive prescribed rehabilitation interventions.

Case presentation

A 67-year-old White Swiss man with two chronic neurological diseases, Parkinson’s disease and multiple sclerosis, underwent a 4-week inpatient rehabilitation in our hospital. The main rehabilitation goals were related to improvements of mobility and a decrease in the risk of falls. The patient gained significant functional improvements that he maintained over the following months, supported by the continuation of physiotherapy in the domestic environment. Due to a coronavirus disease 2019 pandemic-related interruption of the regular ambulatory rehabilitation for several weeks during the first coronavirus disease 2019 wave in Switzerland, the patient’s functional abilities decreased significantly. Thus, the patient was again referred to our hospital for intensive inpatient rehabilitation to regain his physical functioning and mobility capacity. At hospital discharge, the patient improved most of his physical functioning to a prepandemic level.

Conclusions

The interruption of a rehabilitation service due to a pandemic-related lockdown can significantly impact the functional abilities of patients with chronic neurological diseases. This case report supports the claim for continuous access to rehabilitation services for all people with rehabilitation needs.

Psychometric properties of the short form of the Stroke Impact Scale in German-speaking stroke survivors

Background

The short form of the Stroke Impact Scale (SF-SIS) consists of eight questions and provides an overall index of health-related quality of life after stroke. The goal of the study was the evaluation of construct validity, reliability and responsiveness of the SF-SIS for the use in German-speaking stroke patients in rehabilitation.

Methods

The SF-SIS, the Stroke Impact Scale 2.0 (SIS 2.0), EQ-5D-5L, National Institutes of Health Stroke Scale (NIHSS) and de Morton Mobility Index were assessed in 150 inpatients after stroke, with a second measurement two weeks later for the analyses of responsiveness. In 55 participants, the test–retest-reliability was assessed one week after the first measurement. The study was designed following the recommendations of the COSMIN initiative.

Results

The correlations of the SF-SIS with the SIS 2.0 (ρ = 0.90), as well as the EQ-5D-5L (ρ = 0.79) were high, as expected. There was adequate discriminatory ability of the SF-SIS index between patients who were less and more severely affected by stroke, as assessed by the NIHSS. Exploratory factor analysis indicated a two-factor structure of the SF-SIS explaining 59.9% of the total variance, providing better model fit in the confirmatory factor analysis than the one-factorial structure. Analyses of test–retest-reliability showed an intraclass correlation coefficient of 0.88 (95% CI 0.75–0.94). Hypotheses concerning responsiveness were not confirmed due to lower correlations between the assessments change scores.

Conclusion

Results of this analysis of the SF-SIS’s psychometric properties are matching with the validity analysis of the English original version, confirming the high correlations with the Stroke Impact Scale and the EQ-5D-5L. Examination of structural validity did not confirm the presumed unidimensionality of the scale and found evidence of an underlying two-factor solution with a physical and cognitive domain. Sufficient test–retest reliability and internal consistency were found. In addition, this study provides first results for the responsiveness of the German version.

Trial registration The study was registered at the German Clinical Trials Register. Trial registration number: DRKS00011933, date of registration: 07.04.2017

A generic outcome assessment of mobility capacity in neurorehabilitation: measurement properties of the de Morton Mobility Index

Background

Mobility capacity is a key outcome domain in neurorehabilitation. The de Morton Mobility Index (DEMMI), an established and generic outcome assessment of mobility capacity in older patients, is promising for use in neurorehabilitation. The aim of this study was to examine the measurement properties of the DEMMI in rehabilitation inpatients with neurological conditions.

Methods

Cross-sectional study including a mixed sample of adult inpatients in a neurorehabilitation hospital. Structural validity, unidimensionality and measurement invariance (Rasch analysis), construct validity, internal consistency reliability, and inter-rater reliability of the DEMMI (scale range: 0–100 points) were established. The minimal detectable change, the 95% limits of agreement, and possible floor and ceiling effects were calculated to indicate interpretability.

Results

We analyzed validity (n = 348) and reliability (n = 133) in two samples. In both samples, the majority of participants had a sub-acute stroke or Parkinson’s disease.

Rasch analysis indicated unidimensionality with an overall fit to the model (chi-square = 59.4, P = 0.074). There was no relevant measurement invariance by disease group. Hypotheses-based correlation analyses (DEMMI and other functional outcome assessments) showed sufficient construct validity. Internal consistency reliability (Cronbach’s alpha = 0.94) and inter-rater reliability (intraclass correlation coefficient = 0.94; 95% confidence interval: 0.91–0.95) were sufficient. The minimal detectable change with 90% confidence was 15.0 points and the limits of agreement were 39%. No floor or ceiling effects were observed.

Conclusions

Results indicate sufficient measurement properties of the DEMMI in rehabilitation inpatients with neurological conditions. The DEMMI can be used as a generic outcome assessment of mobility capacity in neurorehabilitation.

Trial registration

German Clinical Trials Register (DRKS00004681). Registered May 6, 2013.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02327-0.

An investigation of the measurement properties of the de Morton Mobility Index for measuring mobility capacity in hospital patients with Parkinson's disease

OBJECTIVE

To examine the measurement properties of the de Morton Mobility Index (DEMMI), a performance-based clinical outcome assessment of mobility capacity, in hospital patients with Parkinson's disease.

DESIGN

Cross-sectional study.

PARTICIPANTS

Hospital patients with Parkinson's disease.

MAIN OUTCOME MEASURE(S)

Structural validity and unidimensionality (Rasch analysis), construct validity, internal consistency reliability, and inter-rater reliability of the de Morton Mobility Index (scale range: 0-100 points) were established. The minimal detectable change, the 95% limits of agreement and possible floor and ceiling effects were calculated to indicate interpretability.

RESULTS

We analysed validity (n = 100; mean age: 70 years; 71% male) and reliability (n = 47; mean age: 71 years; 68% male) in two samples. The mean Hoehn and Yahr stage was 3.2 and the mean disease duration was 12 years in both samples. Rasch analysis indicated unidimensionality with an overall fit to the model (chi-square = 21.49, P = 0.122). Seventy-three percent of hypotheses on construct validity were confirmed. Internal consistency reliability (Cronbach's alpha = 0.91) and inter-rater reliability (intraclass correlation coefficient = 0.88; 95% confidence interval: 0.80 to 0.93) were sufficient. The minimal detectable change with 90% confidence was 17.5 points and the limits of agreement were 31%. No floor or ceiling effects were observed. The mean administration time was 6.6 minutes.

CONCLUSION

This study provides evidence of unidimensionality, sufficient internal consistency reliability, inter-rater reliability, construct validity, and feasibility of the de Morton Mobility Index in hospital patients with Parkinson's disease.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS00004681). Registered May 6, 2013.