Development of a multimorbidity illness perceptions scale (MULTIPleS)

Chris J Gibbons; Cassandra Kenning; Peter A Coventry; Penny Bee; Christine Bundy; Louise Fisher; Peter Bower

doi:10.1371/journal.pone.0081852

Development of a multimorbidity illness perceptions scale (MULTIPleS)

PLoS One. 2013 Dec 20;8(12):e81852. doi: 10.1371/journal.pone.0081852. eCollection 2013.

Authors

Chris J Gibbons¹, Cassandra Kenning², Peter A Coventry¹, Penny Bee³, Christine Bundy⁴, Louise Fisher², Peter Bower²

Affiliations

¹ NIHR Collaboration for Leadership in Applied Health Research and Care for Greater Manchester, University of Manchester, Manchester, United Kingdom ; NIHR School for Primary Care Research, NIHR Greater Manchester Primary Care Patient Safety Translational Research Centre, Manchester Academic Health Science Centre (MAHSC), University of Manchester, Manchester, United Kingdom.
² NIHR School for Primary Care Research, NIHR Greater Manchester Primary Care Patient Safety Translational Research Centre, Manchester Academic Health Science Centre (MAHSC), University of Manchester, Manchester, United Kingdom.
³ School of Nursing, Midwifery and Social Work, University of Manchester, Manchester, United Kingdom.
⁴ Manchester Centre for Health Psychology, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom.

Abstract

Background: Illness perceptions are beliefs about the cause, nature and management of illness, which enable patients to make sense of their conditions. These perceptions can predict adjustment and quality of life in patients with single conditions. However, multimorbidity (i.e. patients with multiple long-term conditions) is increasingly prevalent and a key challenge for future health care delivery. The objective of this research was to develop a valid and reliable measure of illness perceptions for multimorbid patients.

Methods: Candidate items were derived from previous qualitative research with multimorbid patients. Questionnaires were posted to 1500 patients with two or more exemplar long-term conditions (depression, diabetes, osteoarthritis, coronary heart disease and chronic obstructive pulmonary disease). Data were analysed using factor analysis and Rasch analysis. Rasch analysis is a modern psychometric technique for deriving unidimensional and intervally-scaled questionnaires.

Results: Questionnaires from 490 eligible patients (32.6% response) were returned. Exploratory factor analysis revealed five potential subscales 'Emotional representations', 'Treatment burden', 'Prioritising conditions', 'Causal links' and 'Activity limitations'. Rasch analysis led to further item reduction and the generation of a summary scale comprising of items from all scales. All scales were unidimensional and free from differential item functioning or local independence of items. All scales were reliable, but for each subscale there were a number of patients who scored at the floor of the scale.

Conclusions: The MULTIPleS measure consists of five individual subscales and a 22-item summary scale that measures the perceived impact of multimorbidity. All scales showed good fit to the Rasch model and preliminary evidence of reliability and validity. A number of patients scored at floor of each subscale, which may reflect variation in the perception of multimorbidity. The MULTIPleS measure will facilitate research into the impact of illness perceptions on adjustment, clinical outcomes, quality of life, and costs in patients with multimorbidity.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Comorbidity
Critical Illness*
Demography
Factor Analysis, Statistical
Humans
Logistic Models
Morbidity*
Nomograms
Reproducibility of Results
Surveys and Questionnaires*

Grants and funding

CJG and PAC are funded by the National Institute of Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care for Greater Manchester. The research funded by the NIHR School for Primary Care Research. The views expressed in this publication are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. The views expressed in this article are those of the authors and not necessarily those of the NIHR. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.