Table 4.
Periodic change in proportion of studies and samples in each study design and sample characteristic category
| Category | Number (%) of studies/samples | Test of proportion | ||||
|---|---|---|---|---|---|---|
| 1990–June 2017 | 1990–2008 | 2009–June 2017 | Direction of change | P value | ||
| Study design | Patient case seriesa | 47 (14.6) | 24 (21.4) | 25 (11.2) | _ | 0.013 |
| Cross-sectional surveyb | 171 (51.0) | 57 (50.9) | 114 (51.1) | + | 0.972 | |
| Longitudinal studies and RCTs without CUAc | 47 (14.0) | 14 (12.5) | 33 (14.8) | + | 0.568 | |
| Longitudinal studies and RCTs with CUA and decision models with primary utility assessmentd | 68 (20.3) | 17 (15.2) | 51 (22.9) | + | 0.099 | |
| Total | 335 | 112 | 223 | |||
| Health condition | General health | 501 (12.6) | 41 (2.9) | 460 (18.0) | + | < 0.001 |
| ICD-10 chapter 1: Infectious and parasitic diseases | 195 (4.9) | 143 (10.0) | 52 (2.0) | _ | < 0.001 | |
| ICD-10 chapter 2: Cancer | 442 (11.1) | 329 (23.1) | 113 (4.4) | _ | < 0.001 | |
| ICD-10 chapter 3: Diseases of the blood and immune system | 85 (2.1) | 49 (3.4) | 36 (1.4) | _ | < 0.001 | |
| ICD-10 chapter 4: Endocrine, nutritional and metabolic disorders | 411 (10.3) | 77 (5.4) | 334 (13.1) | + | < 0.001 | |
| ICD-10 chapter 5: Mental and behavioural disorders | 698 (17.6) | 140 (9.8) | 558 (21.9) | + | < 0.001 | |
| ICD-10 chapter 6: Nervous system disorders | 114 (2.9) | 18 (1.3) | 96 (3.8) | + | < 0.001 | |
| ICD-10 chapter 7: Diseases of the eye | 61 (1.5) | 51 (3.6) | 10 (0.4) | _ | < 0.001 | |
| ICD-10 chapter 8: Diseases of the ear | 158 (4.0) | 70 (4.9) | 88 (3.4) | _ | 0.020 | |
| ICD-10 chapter 9: Circulatory system disorders | 16 (0.4) | 10 (0.7) | 6 (0.2) | _ | 0.014 | |
| ICD-10 chapter 10: Respiratory system disorders | 192 (4.8) | 37 (2.6) | 155 (6.1) | + | < 0.001 | |
| ICD-10 chapter 11: Digestive system disorders | 60 (1.5) | 5 (0.4) | 55 (2.2) | + | < 0.001 | |
| ICD-10 chapter 12: Diseases of the skin | 26 (0.7) | 19 (1.3) | 7 (0.3) | _ | < 0.001 | |
| ICD-10 chapter 13: Musculoskeletal system disorders | 114 (2.9) | 42 (3.0) | 72 (2.8) | _ | 0.717 | |
| ICD-10 chapter 14: Genitourinary system disorders | 56 (1.4) | 7 (0.5) | 49 (1.9) | + | < 0.001 | |
| ICD-10 chapter 16: Conditions originating in the perinatal period | 210 (5.3) | 121 (8.5) | 89 (3.5) | _ | < 0.001 | |
| ICD-10 chapter 17: Congenital malformations | 155 (3.9) | 16 (1.1) | 139 (5.4) | + | < 0.001 | |
| ICD-10 chapter 19: Injury, poisoning and other consequences of external causes | 297 (7.5) | 211 (14.8) | 86 (3.4) | _ | < 0.001 | |
| ICD-10 chapter 21: Contact with health services | 80 (2.0) | 10 (0.7) | 70 (2.7) | + | < 0.001 | |
| Combined chronic diseases | 103 (2.6) | 27 (1.9) | 76 (3.0) | + | 0.037 | |
| Total | 3974 | 1423 | 2551 | |||
| Valuation method | Visual analogue scalese | 832 (20.9) | 230 (16.2) | 602 (23.6) | + | < 0.001 |
| Trade-off-based direct valuation methodsf | 541 (13.6) | 337 (23.7) | 204 (8.0) | _ | < 0.001 | |
| Adult-specific MAUIsg | 476 (12.0) | 130 (9.1) | 346 (13.6) | + | < 0.001 | |
| MAUIs compatible with childhood and adult populationsh | 1537 (38.7) | 660 (46.4) | 877 (34.4) | _ | < 0.001 | |
| Childhood-specific MAUIsi | 573 (14.4) | 63 (4.4) | 510 (20.0) | + | < 0.001 | |
| Utility from non-preference-based methodsj | 15 (0.4) | 3 (0.2) | 12 (0.5) | + | 0.147 | |
| Total | 3974 | 1423 | 2551 | |||
| Respondent type | Self-assessment by children | 1498 (37.7) | 318 (22.3) | 1180 (46.3) | + | < 0.001 |
| Proxy assessment (includes joint assessment by proxies and children) | 2476 (62.3) | 1105 (77.7) | 1371 (53.7) | _ | ||
| Total | 3974 | 1423 | 2551 | |||
| Administration mode | Self-administered surveys | 2464 (62.0) | 609 (42.8) | 1855 (72.7) | + | < 0.001 |
| Interview-administered surveys | 1510 (38.0) | 814 (57.2) | 696 (27.3) | _ | ||
| Total | 3974 | 1423 | 2551 | |||
| Valuation of hypothetical state | Experienced health state | 3247 (81.7) | 1009 (70.9) | 2238 (87.7) | + | < 0.001 |
| Hypothetical health state | 727 (18.3) | 414 (29.1) | 313 (12.3) | _ | ||
| Total | 3974 | 1423 | 2551 | |||
| Age of target population | Sample contains pre-adolescents (mean or median age below 12 or minimum age below 12 if mean/median age not reported) | 2086 (52.5) | 708 (49.8) | 1378 (54.0) | + | 0.011 |
| Sample does not contain pre-adolescents | 1315 (33.1) | 445 (31.3) | 870 (34.1) | + | 0.072 | |
| Sample age not specified | 573 (14.4) | 270 (19.0) | 303 (11.9) | _ | < 0.001 | |
| Total | 3974 | 1423 | 2551 | |||
All values in bold are signify statistically significant results, i.e. p < 0.05
aUtility assessment carried out for a set period of time in a healthcare institution setting on attending patients or inpatients
bSurveys of varying modes of administration such as mail or internet
cLongitudinal observational studies include prospective and retrospective studies
dCost–utility analyses alongside prospective or retrospective observational studies or RCTs and decision modelling studies which carry out primary collection of childhood utility data
eStand-alone VAS, EQ-5D VAS and EQ-5D-Y VAS
fTTO, SG, Chained Gamble and adjusted SG
gEQ-5D, SF-6D, AQoL-5D and 15D
hQWB, HUI2, HUI3, modified HUI and ABC-UI
iEQ-5D-Y, CHU9D, 16D, 17D, AQoL-6D, PAHOM and CH-6D