Six-month and 12-month patient-reported and performance-based physical outcomes for all patients*
| Patient-reported outcome domain—survey instrument† | 6 months (n=233) | 12 months (n=220) | Difference‡ (95% CI) | p Value‡ |
|---|---|---|---|---|
| Quality of life—SF-36 | ||||
| Physical function (norm: 81 (10)) | 49 (32) | 52 (32) | 4 (1 to 6) | 0.005 |
| Physical health summary (norm: 50 (10)) | 37 (12) | 39 (13) | 2 (1 to 3) | 0.003 |
| Mental health (norm: 76 (3)) | 64 (25) | 65 (26) | 0 (−3 to 2) | 0.757 |
| Mental health summary (norm: 50 (10)) | 45 (15) | 45 (15) | 0 (−2 to 2) | 0.923 |
| Quality of life—EQ-5D | ||||
| Utility score | 0.68 (0.24) | 0.69 (0.26) | 0.01 (−0.02 to 0.03) | 0.657 |
| Visual analogue scale | 67 (22) | 71 (21) | 4 (1 to 7) | 0.004 |
| Functional activities—Functional Performance Inventory-Short Form | ||||
| Overall score | 1.9 (0.7) | 2.0 (0.7) | 0.1 (0.0 to 0.2) | 0.037 |
| Physical exercise subscale | 1.5 (0.9) | 1.6 (0.9) | 0.1 (0.0 to 0.2) | 0.062 |
| Maintaining house subscale | 1.7 (0.9) | 1.9 (0.9) | 0.1 (0.0 to 0.2) | 0.006 |
| Body care subscale | 2.5 (0.7) | 2.5 (0.6) | 0.1 (0.0 to 0.1) | 0.152 |
| Mental health symptoms | ||||
| Anxiety score—HADS | 7 (5) | 7 (5) | 0 (−1 to 0) | 0.340 |
| Anxiety ≥8, No (%) | 100 (46) | 84 (41) | −6% (−18 to 6) | 0.343 |
| Depression score—HADS | 6 (5) | 6 (5) | 0 (0 to 1) | 0.523 |
| Depression ≥8, No (%) | 81 (37) | 76 (37) | 0% (−11 to 11) | 0.981 |
| Post-traumatic stress disorder score—IES-R | 1.1 (0.9) | 1.0 (1.0) | 0.0 (−0.1 to 0.1) | 0.418 |
| Post-traumatic stress disorder ≥1.6, No (%) | 55 (25) | 52 (26) | 1% (−8 to 9) | 0.855 |
| Employed, No (%)§ | 42 (19) | 50 (24) | 3% (−1 to 7 ) | 0.123 |
| Performance-based physical outcomes† | 6 months (n=67) | 12 months (n=55) | Difference (95% CI) | p Value‡ |
| 6 min walk distance, % predicted | 65 (24) | 71 (23) | 7 (3 to 11) | 0.001 |
| 4 m gait speed (m/s) | 0.9 (0.3) | 1.0 (0.3) | 0.1 (0.0 to 0.1) | 0.004 |
| Manual muscle test score | 57 (4) | 57 (4) | 0 (0 to 1) | 0.296 |
| Hand grip strength, % predicted | 83 (29) | 91 (32) | 8 (4 to 12) | 0.001 |
| Maximal inspiratory pressure, % predicted | 85 (32) | 98 (32) | 12 (6 to 18) | <0.001 |
| FEV1 % predicted | 77 (21) | 80 (21) | 1 (−1 to 4) | 0.407 |
| FVC % predicted | 77 (20) | 79 (19) | 0 (−2 to 2) | 0.991 |
| BMI (kg/m2) | 29 (8) | 30 (10) | 1 (0 to 1) | 0.027 |
| Arm fat area, % | 35 (12) | 36 (12) | 1 (−1 to 2) | 0.198 |
| Arm muscle area, % | 53 (10) | 53 (10) | −1 (−2 to 1) | 0.366 |
*Mean values (SD) are presented unless otherwise indicated. Number of unknown or missing data for assessments performed at 6 and 12 months, respectively, are: SF-36 physical function 11, 17; SF-36 physical health summary 12, 19; SF-36 mental health 12, 19; SF-36 mental health summary 12, 19; EQ-5D utility score 9, 14; EQ-5D visual analogue scale score 9, 14; FPI overall score 6, 16; FPI physical exercise subscale 6, 15; FPI maintaining house subscale 6, 15; FPI body care subscale 6, 15; anxiety score 16, 17; depression score 16, 17; post-traumatic stress disorder score 17, 22 and employment status 8, 10; 6 min walk test 2, 2; 4 min walk speed 1, 1; manual muscle test score 0, 0; hand grip strength 0, 0; maximal inspiratory pressure 1, 4; FEV1 2, 3; FVC 2, 3; BMI 11, 9; arm fat area 0, 1 and arm muscle area 0, 1.
†Details of test scoring: SF-36 physical function and mental health domains (range: 0–100; higher score is better); SF-36 physical and mental health summary normalised scores (mean=50; SD=10; higher score is better); EQ-5D utility score (range: −0.11 to 1.0; higher score is better) and visual analogue scale score (range: 0–100; higher score is better); FPI-Short Form overall score and subscale scores (for each, range: 0–3; higher score is better); HADS subscale scores for anxiety and depression (for each, range: 0–21; lower score is better, with scores ≥8 indicating substantial symptoms); IES-R (range: 0–4; lower score is better, with scores ≥1.6 indicating substantial symptoms); manual muscle testing score (range: 0–60; higher score is better, with scores <48 indicating ‘ICU-acquired weakness’).
‡Calculations from linear or logistic regression models with random intercept for subject and an indicator for time (12-month vs 6-month follow-up). ‘Difference’ represents the estimated difference between 12 and 6 months in mean score for continuous measures or in proportion for binary measures.
§Employment at 6 and 12 months calculated for all patients regardless of reported baseline employment status.
BMI, body mass index; HADS, Hospital Anxiety and Depression Scale; ICU, intensive care unit; IES-R, Impact of Event Scale—Revised; Norm, mean population norm; SF-36, Medical Outcomes Study Short Form 36 V.2.