Introduction
Myalgic encephalomyelitis/chronic fatigue syndrome
Health state utilities as a measure of health-related quality of life
HSU for people with ME/CFS
Aims of this study
Methods
Survey of people living with ME/CFS
Eligibility criteria and recruitment
The instruments: EQ-5D-5L, AQoL-8D and EQ-5D-5L-psychosocial
EQ-5D-5L | AQoL-8D | EQ-5D-5LPsychosocial | Short Form De Paul Questionnaire | |
---|---|---|---|---|
Dimensions | Five dimensions: Mobility Pain/discomfort Depression/anxiety Self-care Usual activities | Eight individual dimensions: Mental health Coping Happiness Relationships Self-worth Pain Independent living Senses Two super-dimensions: Psychosocial super-dimension Physical super-dimension | Nine dimensions: EQ-5D-5L: Mobility Pain/discomfort Depression/anxiety Self-care Usual activities and Four AQoL-8D bolt-ons: Vitality Sleep Community Connectedness Relationships | Eight dimensions: Fatigue Post exertional malaise Sleep Pain Neurocognitive Autonomic Neuroendocrine Immune |
Items | 5 | 35 | 9 | 54 |
Response levels | 5 | 4–6 | 4–6 | 5 |
Health states | 3125 | 2.4 × 1023 | 1,953,125 | Not applicable |
Measurement unit | Health state utility | Health state utility, super-dimensions (2), and individual dimensions (8) | Health state utility | Frequency and severity rating |
Theoretical scale | 0–1.00 0 worst score/death 1 full health Scores at less than 0 indicate health states worse than death | 0–1.00 0 worst score/death 1 full health | 0–1.00 0 worst score/death 1 full health | 5-point Likert scale 0–4 |
Theoretical utility range | − 0.59 to 1.00 | 0.06–1.00 | 0.06–1.00 | Not Applicable |
Missing values | Not allowed | Up to 10 | Not allowed | Not allowed |
Disability and fatigue severity classifications
Statistical methods
Participant characteristics (n = 198) | |
---|---|
Sociodemographic | |
Age (years) | |
Mean (SD) | 48.7 (14.3) |
Age category, years | n = 197 (%) |
< 45 | 73 (37.1) |
46–84 | 124 (62.9) |
Gender | n = 198 (%) |
Male | 32 (16.2) |
Female | 158 (79.8) |
Other | 8 (4.0) |
Education | n = 197 (%) |
≤ Year 12 | 25 (12.7) |
Trade* | 40 (20.3) |
Bachelors | 65 (33.0) |
Postgraduate | 67 (34.0) |
Employment | n = 172 (%) |
Too unwell to be employed | 80 (46.5) |
Unemployed | n/r |
Retired | 19 (11.1) |
Full time | 12 (7.0) |
Part time | 46 (26.7) |
Student | 6 (3.5) |
Other | 6 (3.5) |
Income ($AUD) | n = 195 (%) |
Nil/negative income | 25 (12.8) |
< 400/week | 51 (26.2) |
400–799/week | 79 (40.5) |
800–1249/week | 17 (8.7) |
≥ 1250/week | 23 (11.8) |
Marital status | n = 198 (%) |
Married/De facto | 87 (43.9) |
Divorced/separated | 30 (15.2) |
Single | 77 (38.9) |
Widowed | n/r |
Geographical remoteness* | n = 192 (%) |
Major capital city | 113 (58.9) |
Inner regional | 54 (28.1) |
Outer regional | 25 (13.0) |
Clinical | |
Disability severity | n = 198 (%) |
No | n/r |
Mild | 40 (20.2) |
Moderate | 137 (69.2) |
Severe | 19 (9.6) |
Fatigue severity | n = 198 (%) |
No | n/r |
Mild | 22 (11.1) |
Moderate | 118 (59.6) |
Severe | 56 (28.3) |
Comorbidities n (%) | n = 198 (%) |
0 | 128 (64.7) |
1 | 48 (24.2) |
2 | 18 (9.1) |
3 | n/r |
EQ-5D-5L | AQoL-8D | EQ-5D-5L-Psychosocial | ||||
---|---|---|---|---|---|---|
Mean (95% CI) | Range | Mean (95% CI) | Range | Mean (95% CI) | Range | |
Overall sample | 0.46 (0.42−0.50) | − 0.50–1.00 | 0.44 (0.42–0.45) | 0.15–0.99 | 0.44 (0.42–0.46) | 0.11–0.98 |
Sociodemographic | ||||||
Age group (years) | ||||||
< 45 | 0.37 (0.30–0.44) | − 0.43–0.86 | 0.41 (0.37–0.43) | 0.15–0.76 | 0.41 (0.38–0.44) | 0.12–0.78 |
46–84 | 0.51 (0.45–0.57) | − 0.50–1.00 | 0.46 (0.41–0.49) | 0.16–0.99 | 0.46 (0.43–0.49) | 0.11–0.91 |
Gender | ||||||
Male | 0.53 (0.44–0.62) | − 0.11–1.00 | 0.47 (0.40–0.54) | 0.16–0.99 | 0.46 (0.40–0.52) | 0.14–0.91 |
Female | 0.45 (0.40–0.50) | − 0.50–1.00 | 0.44 (0.42–0.46) | 0.15–0.99 | 0.44 (0.42–0.46) | 0.11–0.98 |
Other | 0.35 (− 0.01 to 0.71) | − 0.43–0.81 | 0.38 (0.26–0.50) | 0.17–0.64 | 0.38 (0.25–0.51) | 0.15–0.59 |
Education level | ||||||
≤ Year 12 | 0.44 (0.27–0.61) | − 0.43–1.00 | 0.42 (0.35–0.49) | 0.17–0.99 | 0.42 (0.35–0.49) | 0.15–0.98 |
Trade | 0.39 (0.30–0.48) | − 0.17–0.81 | 0.40 (0.36–0.44) | 0.15–0.74 | 0.39 (0.35–0.43) | 0.12–0.65 |
Bachelors | 0.46 (0.38–0.54) | − 0.50–1.00 | 0.44 (0.41–0.47) | 0.16–0.82 | 0.45 (0.42–0.48) | 0.11–0.75 |
Postgraduate | 0.51 (0.44–0.58) | − 0.19–1.00 | 0.48 (0.44–0. 52) | 0.20–0.99 | 0.48 (0.44–0.52) | 0.16–0.91 |
Employment | ||||||
Unwell | 0.40 (0.33–0.47) | − 0.43–1.00 | 0.40 (0.37–0.43) | 0.16–0.76 | 0.40 (0.37–0.43) | 0.12–0.68 |
Unemployed | 0.46 (0.06–0.86) | 0.34–0.64 | 0.45 (− 0.07 to 0.97) | 0.28–0.68 | 0.43 (0.13–0.73) | 0.33–0.56 |
Retired | 0.63 (0.50–0.76) | − 0.13–0.92 | 0.57 (0.48–0.66) | 0.25–0.87 | 0.56 (0.49–0.63) | 0.27–0.75 |
Full-time | 0.70 (0.60–0.80) | 0.49–0.92 | 0.55 (0.46–0.64) | 0.33–0.78 | 0.55 (0.46–0.64) | 0.28–0.78 |
Part-time | 0.51 (0.43–0.59) | − 0.06–1.00 | 0.46 (0.42–0.50) | 0.15–0.99 | 0.45 (0.41–0.49) | 0.12–0.91 |
Student | 0.52 (0.31–0.73) | 0.32–0.81 | 0.45 (0.31–0.59) | 0.29–0.64 | 0.42 (0.30–0.54) | 0.29–0.59 |
Other | 0.62 (0.55–0.69) | 0.49–0.67 | 0.46 (0.36–0.54) | 0.32–0.59 | 0.49 (0.42–0.56) | 0.34–0.54 |
Income | ||||||
Nil/negative income | 0.45 (0.32–0.58) | − 0.11–1.00 | 0.47 (0.38–0.54) | 0.23–0.99 | 0.45 (0.37–0.53) | 0.14–0.98 |
≤ 399/week | 0.42 (0.32–0.52) | − 0.50–1.00 | 0.39 (0.34–0.42) | 0.16–0.76 | 0.40 (0.36–0.44) | 0.11–0.69 |
400–799/week | 0.42 (0.35–0.49) | − 0.42–1.00 | 0.43 (0.39–0.45) | 0.16–0.76 | 0.43 (0.40–0.46) | 0.14–0.69 |
800–1249/week | 0.53 (0.39–0.67) | − 0.17–0.92 | 0.50 (0.39–0.57) | 0.28–0.87 | 0.48 (0.40–0.56) | 0.18–0.75 |
≥ 1250/week | 0.63 (0.53–0.73) | < − 0.01–1.00 | 0.52 (0.42–0. 58) | 0.15–0.99 | 0.51 (0.44–0.58) | 0.12–0.91 |
Marital status | ||||||
Single | 0.36 (0.28–0.44) | − 0.43–1.00 | 0.41 (0.38–0.44) | 0.15–0.99 | 0.40 (0.37–0.43) | 0.12–0.98 |
Married | 0.53 (0.47–0.59) | − 0.50–1.00 | 0.47 (0.44–0.50) | 0.16–0.87 | 0.47 (0.44–0.50) | 0.11–0.78 |
Divorced/separated | 0.47 (0.36–0.58) | − 0.08–0.92 | 0.43 (0.38–0.48) | 0.20–0.68 | 0.43 (0.37–0.49) | 0.12–0.73 |
Widowed | 0.69 (0.29–1.00) | 0.39 to 1.00 | 0.64 (0.19–1.00) | 0.40–0.99 | 0.60 (0.23–0.97) | 0.40–0.91 |
Geographical remoteness area | ||||||
Major city | 0.45 (0.39–0.51) | − 0.50–1.00 | 0.44 (0.41–0.47) | 0.16–0.99 | 0.44 (0.41–0.47) | 0.11–0.91 |
Inner regional | 0.49 (0.41–0.57) | − 0.24–1.00 | 0.45 (0.41–0.49) | 0.15–0.99 | 0.44 (0.40–0.48) | 0.12–0.98 |
Outer regional | 0.45 (0.31–0.59) | − 0.28–1.00 | 0.46 (0.31–0.51) | 0.25–0.74 | 0.44 (0.38–0.50) | 0.14–0.65 |
Clinical | ||||||
Disability severity | ||||||
No | 1.00 (1.00–1.00) | 1.00–1.00 | 0.99 (0.90–1.00) | 0.99–0.99 | 0.94 (0.49–1.00) | 0.91–0.98 |
Mild | 0.69 (0.63–0.75) | − 0.11–1.00 | 0.57 (0.53–0.61) | 0.27–0.87 | 0.55 (0.51–0.59) | 0.29–0.75 |
Moderate | 0.44 (0.39–0.49) | − 0.43–1.00 | 0.42 (0.40–0.44) | 0.16–0.76 | 0.43 (0.41–0.45) | 0.14–0.78 |
Severe | 0.02 (− 0.13–0.17) | − 0.50–0.63 | 0.30 (0.25–0.35) | 0.15–0.55 | 0.25 (0.20–0.30) | 0.11–0.46 |
Fatigue severity | ||||||
No | 1.00 (1.00–1.00) | 1.00–1.00 | 0.99 (0.90–1.00) | 0.99–0.99 | 0.94 (0.49–1.00) | 0.91–0.98 |
Mild | 0.69 (0.62–0.78) | 0.33–1.00 | 0.61 (0.54–0.68) | 0.27–0.87 | 0.57 (0.52–0.62) | 0.29–0.75 |
Moderate | 0.55 (0.51–0.59) | − 0.17–1.00 | 0.45 (0.43–0.47) | 0.16–0.76 | 0.47 (0.45–0.49) | 0.14–0.78 |
Severe | 0.16 (0.08–0.24) | − 0.50–0.67 | 0.34 (0.31–0.37) | 0.15–0.60 | 0.31 (0.28–0.34) | 0.11–0.56 |
Comorbidities | ||||||
0 | 0.46 (0.40–0.52) | − 0.49–1.00 | 0.44 (0.41–0.47) | 0.16–0.99 | 0.44 (0.41–0.47) | 0.11–0.98 |
1 | 0.49 (0.40–0.58) | − 0.42–1.00 | 0.47 (0.43–0.51) | 0.15–0.82 | 0.45 (0.41–0.49) | 0.12–0.78 |
2 | 0.43 (0.28–0.58) | − 0.07–0.86 | 0.38 (0.32–0.44) | 0.23–0.65 | 0.41 (0.34–0.48) | 0.14–0.69 |
3 | 0.36 (− 0.46 to 1.00) | 0.38 to 0.65 | 0.30 (0.08–0.52) | 0.19–0.38 | 0.31 (0.01–0.61) | 0.18–0.43 |
MAUI (N = 198) | ||||
---|---|---|---|---|
Floor | Ceiling | |||
Mean (SD) | % | Mean (SD) | % | |
EQ-5D-5L | 0.11 (0.20) | 27 (13.6) | 1.00 (0.00) | 5 (2.5) |
AQoL-8D | 0.29 (0.09) | 0 | 0.70 (0.26) | 0 |
EQ-5D-5L-PSYCHOSOCIAL | 0.25 (0.10) | 0 | 0.74 (0.19) | 0 |
Bolt-on dimensions | Levels of responses n (%) | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Participants with floor effect ( n = 27) | Participants without floor effect ( n = 171) | |||||||||
Worst response | Worst response | |||||||||
Level 1 | Level 2 | Level 3 | Level 4 | Level 5 | Level 1 | Level 2 | Level 3 | Level 4 | Level 5 | |
**Energy | 0 | 0 | 0 | 3 (11) | 24 (89) | 0 | 2 (1) | 27 (16) | 56 (33) | 86 (50) |
Relationships | 3 (11) | 11 (41) | 6 (22) | 3 (11) | 4 (15) | 38 (22) | 80 (47) | 30 (18) | 19 (11) | 4 (2) |
Sleeping | 0 | 1 (4) | 7 (26) | 11 (41) | 8 (30) | 3 (2) | 14 (8) | 59 (35) | 57 (33) | 38 (22) |
*Social solation | 0 | 0 | 0 | 11 (41) | 16 (59) | 8 (5) | 15 (9) | 69 (40) | 51 (30) | 28 (16) |
Univariable | EQ-5D-5L | AQoL-8D | EQ-5D-5L Psychosocial | |||
---|---|---|---|---|---|---|
β (95% CI) | p-value | β (95% CI) | p-value | β (95% CI) | p-value | |
Age group (years) | ||||||
< 45 | Reference | Reference | Reference | |||
> 45 & ≤ 84 | 0.13 (0.04–0.22)* | < 0.01 | 0.04 (<− 0.01 to − 0.09) | 0.07 | 0.05 (0.01–0.09)* | 0.02 |
Gender | ||||||
Male | Reference | Reference | Reference | |||
Female | − 0.08 (− 0.20 to − 0.04) | 0.18 | − 0.03 (− 0.09 to − 0.03) | 0.39 | − 0.02 (− 0.08 to 0.04) | 0.53 |
Education | ||||||
≤ Year 12 | Reference | Reference | Reference | |||
Trade | − 0.05 (− 0.21 to − 0.11) | 0.55 | − 0.02 (− 0.10 to 0.05) | 0.56 | − 0.03 (− 0.10 to 0.05) | 0.50 |
Bachelors | 0.02 (− 0.12 to 0.17) | 0.75 | 0.02 (− 0.06 to 0.09) | 0.67 | 0.03 (− 0.04 to 0.10) | 0.36 |
Postgraduate | 0.07 (− 0.07 to 0.22) | 0.33 | 0.06 (− 0.01 to 0.13) | 0.11 | 0.06 (− 0.01 to − 0.13) | 0.08 |
Employment | ||||||
Unwell | Reference | Reference | Reference | |||
Unemployed | 0.06 (− 0.27 to 0.39) | 0.72 | 0.06 (− 0.11 to 0.22) | 0.49 | 0.02 (− 0.13 to 0.18) | 0.76 |
Retired | 0.24 (0.09 to 0.38)* | < 0.01 | 0.18 (0.11–0.25)* | < 0.01 | 0.16 (0.09–0.22)* | < 0.01 |
Full-time | 0.30 (0.13 to 0.48)* | < 0.01 | 0.16 (0.07–0.24)* | < 0.01 | 0.15 (0.06–0.23)* | < 0.01 |
Part-time | 0.11 (0.01 to 0.21)* | 0.04 | 0.07 (0.02–0.12)* | 0.01 | 0.05 (9.82e−06 to − 0.10)* | 0.05 |
Student | 0.13 (− 0.11 to 0.37) | 0.28 | 0.05 (− 0.07 to 0.17) | 0.39 | 0.02 (− 0.10 to 0.13) | 0.78 |
Other | 0.22 (− 0.02 to − 0.46) | 0.07 | 0.06 (− 0.06 to − 0.17) | 0.33 | 0.08 (− 0.03 to − 0.20) | 0.14 |
Income | ||||||
Nil/negative income | Reference | Reference | Reference | |||
≤ 399/week | − 0.03 (− 0.18 to 0.12) | 0.70 | − 0.08 (− 0.15 to − 0.01)* | 0.03 | − 0.05 (− 0.13 to 0.02) | 0.13 |
400–799/ week | − 0.03 (− 0.17 to 0.12) | 0.73 | − 0.04 (− 0.10 to 0.03) | 0.31 | − 0.02 (− 0.09 to 0.04) | 0.47 |
800–1249/week | 0.08 (− 0.11 to 0.28) | 0.41 | 0.03 (− 0.06 to 0.12) | 0.54 | 0.02 (− 0.07 to 0.12) | 0.60 |
≥ 1250/week | 0.18 (< − 0.01 to − 0.36)* | 0.05 | 0.06 (− 0.03 to − 0.14) | 0.20 | 0.05 (− 0.03 to 0.14) | 0.24 |
Marital status | ||||||
Single | Reference | Reference | Reference | |||
Married | 0.16 (0.07–0.26)* | < 0.01 | 0.06 (0.01–0.11)* | 0.01 | 0.08 (0.03–0.12)* | < 0.01 |
Divorced/separated | 0.11 (− 0.02 to 0.24) | 0.10 | 0.02 (− 0.05 to 0.08) | 0.59 | 0.03 (− 0.03 to 0.10) | 0.29 |
Geographical Remoteness area | ||||||
Major city | Reference | Reference | Reference | |||
Inner regional | 0.03 (− 0.07 to 0.14) | 0.55 | < 0.01 (− 0.05 to 0.06) | 0.86 | < 0.01 (− 0.05 to 0.05) | 0.97 |
Outer regional | < − 0.01 (− 0.15 to 0.14) | 0.96 | 0.01 (− 0.05 to 0.08) | 0.67 | < 0.01 (− 0.06 to 0.07) | 0.94 |
Disability severity | ||||||
No | Reference | Reference | Reference | |||
Mild | − 0.31 (− 0.67 to 0.07) | 0.11 | − 0.42 (− 0.60 to − 0.24)* | < 0.01 | − 0.39 (− 0.56 to − 0.22)* | < 0.01 |
Moderate | − 0.56 (− 0.93 to − 0.18)* | < 0.01 | − 0.57 (− 0.75 to − 0.39)* | < 0.01 | − 0.52 (− 0.68 to − 0.35)* | < 0.01 |
Severe | − 0.98 (− 1.37 to − 0.59)* | < 0.01 | − 0.69 (− 0.88 to − 0.51)* | < − 0.01 | − 0.70 (− 0.87 to − 0.52)* | < 0.01 |
Fatigue severity | ||||||
No | Reference | Reference | Reference | |||
Mild | − 0.31 (− 0.67 to − 0.06) | 0.10 | − 0.38 (− 0.56 to − 0.20)* | < 0.01 | − 0.37 (− 0.54 to − 0.20)* | < 0.01 |
Moderate | − 0.45 (− 0.80 to − 0.10)* | 0.01 | − 0.54 (− 0.71 to − 0.36)* | < 0.01 | − 0.47 (− 0.64 to − 0.31)* | < 0.01 |
Severe | − 0.84 (− 1.20 to − 0.49)* | < 0.01 | − 0.65 (− 0.83 to − 0.48)* | < 0.01 | − 0.63 (− 0.80 to − 0.47)* | < 0.01 |
Comorbidity | ||||||
0 | Reference | Reference | Reference | |||
1 | 0.03 (− 0.08 to 0.14) | 0.60 | 0.03 (− 0.02 to 0.08) | 0.25 | 0.01 (− 0.04 to 0.06) | 0.64 |
2 | − 0.03 (− 0.19 to 0.13) | 0.72 | − 0.06 (− 0.14 to 0.01) | 0.10 | − 0.03 (− 0.10 to 0.05) | 0.45 |
3 | 0.10 (− 0.42 to 0.22) | 0.54 | − 0.15 (− 0.30 to 0.01) | 0.07 | − 0.14 (− 0.29 to 0.01) | 0.08 |