Measuring needs-based quality of life and self-perceived health inequity in patients with multimorbidity: investigating psychometric measurement properties of the MultiMorbidity Questionnaire (MMQ) using primarily Rasch models

Bissenbakker, Kristine; Siersma, Volkert; Jønsson, Alexandra Brandt Ryborg; Møller, Anne; Christensen, Karl Bang; Brodersen, John Brandt

doi:10.1186/s41687-023-00633-4

Journal of Patient-Reported Outcomes

Table 6 Fit statistics, Cronbach’s alpha, number of respondents and proportion with significant person misfit for each scale in the MMQ1 and MMQ2 after removing items with poor fit or DIF

From: Measuring needs-based quality of life and self-perceived health inequity in patients with multimorbidity: investigating psychometric measurement properties of the MultiMorbidity Questionnaire (MMQ) using primarily Rasch models

Scale	No. of items	Item pairs with LRD^a	Respondents (N)	Fit to graphical Rasch model			Cronbach’s alpha	PSI^c	Proportion with misfit (95% CI)
Scale	No. of items	Item pairs with LRD^a		CLR-X²	df	P^b	Cronbach’s alpha	PSI^c	Proportion with misfit (95% CI)
MMQ1
1. Physical ability	6	2	345	22.1	30	0.8504	0.86589	0.81172	8.7% (5.7% to 11.7%)
2. Worries	6	3	320	56.8	42	0.0628	0.87617	0.84896	6.9% (4.1% to 9.6%)
3. Limitations in everyday life	10	3	332	90.4	73	0.0818	0.92304	0.88394	8.7% (5.6% to 11.7%)
4. My social life	6	2	295	19.7	35	0.9829	0.87450	0.74587	5.4% (2.8% to 8.0%)
5. Self-image	6	4	301	65.6	52	0.0975	0.89459	0.74587	6.0% (3.3% to 8.9%)
6. Personal finances	3	1	224	10.1	17	0.9013	0.86525	0.59626	3.1% (0.8% to 5.4%)
MMQ2
In encounter with: The general practitioner
7. Experience of being stigmatised	5	–	126	27.9	14	0.0146	0.88408	–	–
8. Experience of not being seen and heard	4	–	117	29.3	11	0.0020	0.95804	–	–
9. Experience of insufficient understanding of the burden of disease	3	–	125	3.3	8	0.9170	0.97467	–	–
10. Experience of powerlessness	5	–	143	15.3	14	0.3554	0.95682	–	–
Staff at the general practitioner’s surgery
11. Experience of being stigmatised	5	–	73	5.4	13	0.9653	0.89769	–	–
12. Experience of not being seen and heard	4	–	66	7.8	11	0.7300	0.92431	–	–
13. Experience of insufficient understanding of the burden of disease	3	–	54	1.2	8	0.9963	0.97630	–	–
Other healthcare professionals
14. Experience of being stigmatised	5	–	47	18.7	13	0.1313	0.83708	–	–
15. Experience of not being seen and heard	4	–	50	8.5	11	0.6696	0.88595	–	–
16. Experience of insufficient understanding of the burden of disease	3	–	50	2.4	8	0.9677	0.97037	–	–
17. Experience of powerlessness	5	–	79	22.3	13	0.0507	0.86294	–	–
Local authorities
18. Experience of being stigmatised	5	–	53	17.5	14	0.2303	0.91315	–	–
19. Experience of not being seen and heard	4	–	53	19.9	10	0.0307	0.90314	–	–
20. Experience of insufficient understanding of the burden of disease	3	–	51	10.7	8	0.2204	0.98124	–	–
21. Experience of powerlessness	5	–	64	24.4	14	0.0409	0.95179	–	–
Family, friends and others
22. Experience of being stigmatised	4	–	134	21	11	0.0329	0.85922	–	–
23. Experience of insufficient understanding of the burden of disease	3	–	165	8.4	8	0.3974	0.95969	–	–

^aLocal Response Dependency (LRD). Indicating the number of items within each scale that are correlated beyond the construct measured in terms of content, structure or wordings
^bThe Benjamini–Hochberg adjusted significance levels rejects fit below the usual significance level of 0.05 to account for spurious significant results due to multiple testing. The adjusted p value is calculated for each scale fit to the Rasch Model
^cPerson Separation Index (PSI) for each scale. A reliability index that is indicative of the power of the construct to discriminate amongst respondents where 0.7 is minimum. PSI and proportion with misfit have not been reported due to the low sample size of MMQ2

Back to article page