The prevalence and severity of disease-related disabilities and their impact on quality of life in neuromuscular diseases

Figures & data

Table 1. Sample characteristics for the total sample (n = 662) and subgroups.

	Total sample(n = 662)	Motor-neuron disorders(n = 62)	Muscle disorders(n = 155)	Junction disorders(n = 177)	Peripheral nerve disordersprimary motor(n = 71)	Peripheral nerve disordersprimary sensor(n = 197)
Gender n (%)
Female	335 (51)	31 (50)	77 (50)	115 (65)	32 (45)	80 (41)
Age (years)
Mean (SD)	59 (15.4)	60.8 (12.7)	51.6 (16.8)	58.7 (15.7)	55.7 (14.4)	65.3 (12.3)
Range	19–92	29–86	19–92	22–89	26–82	32–91
Relationship status n (%)
Married/partnership	468 (71)	51 (82)	95 (61)	128 (72)	52 (73)	142 (72)
Unmarried/widowed/divorced	193 (29)	11 (18)	60 (39)	48 (27)	19 (27)	55 (28)
Educational level n (%)
Lower level	480 (73)	41 (66)	114 (75)	131 (74)	51 (73)	143 (73)
Higher level	177 (27)	21 (34)	37 (25)	46 (26)	19 (27)	54 (27)
Employment status n (%)
Employment	187 (28)	18 (29)	46 (30)	60 (34)	21 (30)	42 (21)
Unemployment	475 (72)	44 (71)	109 (70)	117 (66)	50 (70)	155 (79)
Range	0–65	1–64	1–62	0–65	0–55	0–61
Health-state
EQ-VAS, median (IQR)	67 (30)	65 (23)	65 (25)	70 (25)	70 (30)	65 (30)
Extent of limitations
Median (IQR)	5 (4)	7 (3)	6 (5)	5 (3)	6 (4)	6 (5)
Quality of Life
QoL-rate, median (IQR)	7 (2)	7 (2)	7 (2)	7 (2)	7 (1)	7 (2)

IQR: Inter quartile range.

Table 2. Prevalence and severity of disease-related disabilities in the total sample and in disease subgroups.

	Total sample (n = 662)				Motor-neuron disorders (n = 62)				Muscle disorders (n = 155)				Junction disorders (n= 177)				Peripheral nervedisorders primary motor (n = 71)				Peripheral nervedisorders primarysensor (n = 197)				Subgroup differences#
	%	mean	(CI)	SD	%	mean	(CI)	SD	%	mean	(CI)	SD	%	mean	(CI)	SD	%	mean	(CI)	SD	%	mean	(CI)	SD	Chi-Square	p
Impairments in…
Muscle functions	94	44.8	(43.0–46.6)	23.0	98	58.7	(52.3–65.0)	25.0	99	52.4	(48.9–55.9)	21.8	93	35.3	(32.3–38.2)	19.1	93	44.3	(39.0-49.6)	22.2	91	42.3	(38.9–45.6)	22.5	66.8	<0.001
Movement functions	70	22.0	(20.5–23.4)	17.7	76	33.5	(27.7–39.3)	20.5	69	21.5	(18.4–24.6)	17.6	58	13.6	(11.4–15.7)	13.3	86	23.4	(19.2–27.5)	16.7	91	25.9	(23.2–28.6)	17.5	66.7	<0.001
Excretion and reproductive functions	47	15.9	(14.3–17.4)	17.2	53	16.1	(10.7–21.5)	18.1	43	15.8	(12.7–19.0)	16.6	48	14.0	(11.5–16.5)	14.2	51	12.3	(27.7–39.3)	17.8	67	18.8	(15.6–22.0)	19.2	7.3	0.119
Swallowing and speech functions	38	9.3	(21.4–23.9)	15.1	37	13.8	(7.7–19.8)	23.4	51	14.0	(11.2–16.7)	16.8	50	11.5	(9.5–13.4)	13.0	19	4.0	(1.6–6.5)	10.0	26	4.4	(3.2–5.6)	8.4	59.1	<0.001
Mental Functions and Pain	79	22.6	(21.4–23.9)	15.1	87	21.5	(17.7–25.3)	14.4	80	24.3	(21.5–27.1)	16.1	79	21.2	(18.9–23.5)	14.4	89	18.3	(14.8–21.8)	13.7	95	24.7	(22.3–27.1)	15.4	10.5	0.033
Seeing functions	40	15.3	(13.7–17.0)	20.8	21	5.7	(2.8–8.7)	11.5	37	14.4	(11.0–17.8)	20.8	68	26.2	(22.8–29.5)	22.5	20	7.2	(2.9–11.5)	17.4	34	11.8	(9.1–14.5)	18.3	86.4	<0.001
Limitations in…
Activities of Moving Around	86	30.6	(28.5–32.7)	27.4	98	48.8	(40.5–57.1)	32.7	95	41.3	(36.6–45.9)	29.3	73	16.4	(13.7–19.1)	18.0	83	28.9	(23.1–34.7)	24.5	88	29.9	(26.4–33.5)	25.4	99.2	<0.001
Self-care and Domestic Activities	76	21.8	(19.8–23.8)	26.5	98	48.0	(38.7–57.1)	36.2	86	31.0	(26.1–35.8)	30.5	68	11.7	(9.4–14.0)	15.5	75	17.3	(12.7–21.9)	19.4	70	17.3	(14.2–20.4)	22.1	85.6	<0.001
Restrictions in…
Participation in Life Situations	52	15.1	(19.8–23.9)	26.5	63	25.3	(18.3–32.2)	27.0	65	20.7	(17.0–24.3)	22.8	39	9.3	(6.9–11.8)	16.4	49	11.7	(7.4–15.9)	17.8	53	13.9	(11.3–16.6)	19.0	40.2	<0.001
Lack of support from…
Immediate family	35	23.8	(21.1–26.5)	35.1	27	16.1	(8.9–23.3)	28.3	37	24.8	(19.2–30.5)	35.8	34	21.2	(16.4–26.0)	32.2	32	21.1	(13.2–29.0)	33.4	39	28.8	(23.2–34.3)	39.1	5.9	0.204
Social security services	21	35.5	(30.9–40.1)	38.2	20	28.6	(14.2–43.0)	37.1	28	36.4	(28.0–44.7)	36.8	18	33.6	(24.1–43.0)	37.9	57	42.9	(28.3–57.4)	42.3	52	35.3	(25.2–45.5)	38.6	2.3	0.686
Health services	48	32.0	(30.9–40.1)	36.7	55	33.9	(25.0–42.7)	34.8	52	34.6	(28.8–40.5)	36.9	42	28.2	(22.8–33.7)	36.4	39	26.1	(17.6–34.5)	35.7	52	34.9	(29.5–40.3)	37.7	6.8	0.145

%Prevalence, severity (mean disability) score: score 0: no disability; score 100: complete disability. ‘Lack of support’ score 0: no support, score 100: full support.

# Independent Kruskal–Wallis test; CI: confidence interval.

Table 3. Impact of disease-related disabilities on the SF-36 QoL variables.

SF-36	Physicalfunctioning ß	Role Physical ß	Bodilypain ß	Vitality ß	Socialfunctioning ß	Roleemotional ß	Mentalhealth ß	Generalhealth ß
NMDIP
Impairments in ….
Muscle functions	–0.20**	–0.06	0.12	–0.14	–0.07	0.21	–0.02	–0.08
Movement functions	0.09	–0.01	–0.06	0.14	–0.06	–0.02	–0.10	–0.10
Excretion and reproductive functions	–0.00	–0.11	0.04	–0.04	–0.11	–0.06	0.11	–0.14
Swallowing and speech functions	0.04	–0.01	–0.10	–0.11	0.11	0.08	–0.13	–0.02
Mental functions and pain	–0.08	–0.16	–0.59***	–0.53***	–0.36***	–0.40**	–0.34**	–0.36**
Seeing functions	0.09	–0.00	0.11*	0.09	–0.09	–0.02	–0.00	–0.01
Limitations in ….
Activities of moving around	–0.57***	0.20	–0.08	0.02	0.24	0.29	0.15	0.19
Self-care and domestic activities	–0.11	0.15	–0.04	0.13	–0.17	–0.42**	–0.03	–0.10
Restrictions in ….
Participation in life situations	–0.10	–0.46***	–0.09	–0.08	–0.32**	–0.07	–0.12	–0.15
Lack of support from….
Immediate family	0.04	0.04	0.02	0.04	0.01	0.01	0.13	0.03
Social security services	–0.06	0.00	–0.05	–0.02	0.05	–0.12	–0.03	0.03
Health services	0.02	0.03	–0.05	–0.01	–0.07	0.04	–0.01	0.01
R^2	0.73	0.31	0.52	0.51	0.49	0.27	0.29	0.43
ΔR^2#	0.66	0.22	0.41	0.33	0.38	0.19	0.24	0.31
F	20.7***	3.5***	8.35***	7.92***	7.33***	2.92***	3.23***	5.83***
F Change#	26.78***	3.47***	9.35***	7.26***	8.01***	2.91**	3.69***	5.91***

* =p < 0.05;

** =p < 0.01;

*** =p < 0.001.

In bold: statistically significant sz values.

# = compares Model 2 (disabilities) vs. Model 1 (patient characteristics).

Table 4. Impact of disease-related disabilities on the WHOQOL-bref QoL variables.

WHOQOL-bref	Physical health ß	Psychological health ß	Social relationships ß	Environment ß
NMDIP
Impairments in ….
Muscle functions	–0.09	–0.03	0.02	–0.01
Movement functions	0.06	0.10	0.20	0.21*
Excretion and reproductive functions	–0.05	–0.13	–0.41***	–0.03
Swallowing and speech functions	–0.06	–0.05	0.14	–0.06
Mental functions and pain	–0.54***	–0.28*	–0.21	–0.21
Seeing functions	0.09	–0.11	–0.08	–0.05
Limitations in ….
Activities of moving around	–0.04	0.19	0.00	–0.13
Self-care and domestic activities	0.07	–0.04	–0.13	–0.13
Restrictions in ….
Participation in life situations	–0.21*	–0.25*	–0.14	–0.27*
Lack of support from ….
Immediate family	0.01	0.00	–0.20**	–0.24**
Social security services	–0.12	–0.07	–0.21*	–0.07
Health services	0.09	–0.05	0.09	–0.07
R^2	0.70	0.30	0.38	0.43
ΔR^2#	0.46	0.23	0.34	0.36
F	17.94***	3.33***	4.76***	5.86***
F Change#	16.60***	3.58***	5.99***	6.86***

* =p < 0.05.

** =p < 0.01.

*** =p < 0.001.

In bold: statistically significant sz values.

# = compares Model 2 (disabilities) vs. Model 1 (patient characteristics).