Background
Methods
Study design
Sampling
Data
Value sets compared
The Swedish value sets
The German value sets
The Danish value sets
The UK value sets
Data entry, analysis, and interpretation
Baseline characteristics of patients across ASA classes
One-way analysis of variance (ANOVA)
Ordinary least squares regression (OLS) and prediction error measures
Results
Demographic and clinical characteristics of THR patients at baseline
Variable | ASA class | P-value | Cramer’s V / Kendall tau | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Total | Class I | Class II | Class III | Class IV | ||||||||
% | n | % | n | % | n | % | n | % | n | |||
Sex | 0.352 | 0.053 | ||||||||||
Men | 43.2 | 29,965 | 46.0 | 8191 | 41.2 | 17,074 | 47.0 | 4584 | 53.0 | 116 | ||
Women | 56.8 | 39,325 | 54.0 | 9631 | 58.8 | 24,418 | 53.0 | 5173 | 47.0 | 103 | ||
Age (years) [mean (SD)] | 68.2 (10.2) | 62.7 (10.4) | 69.4 (9.4) | 72.9 (9.2) | 73.5 (10.1) | < 0.001 | – | |||||
Age group (years) | < 0.001 | 0.282d | ||||||||||
< 50 | 4.7 | 3246 | 11.2 | 1995 | 2.6 | 1094 | 1.5 | 151 | 2.7 | 6 | ||
50–59 | 13.5 | 9351 | 23.9 | 4251 | 10.8 | 4485 | 6.1 | 600 | 6.8 | 15 | ||
60–69 | 34.4 | 23,822 | 38.6 | 6886 | 34.8 | 14,453 | 24.9 | 2433 | 22.8 | 50 | ||
70–79 | 34.5 | 23,906 | 22.4 | 3986 | 37.9 | 15,720 | 42.2 | 4122 | 35.6 | 78 | ||
80–95 | 12.9 | 8965 | 4.0 | 704 | 13.8 | 5740 | 25.1 | 2451 | 32.0 | 70 | ||
BMI categorya | < 0.001 | 0.155d | ||||||||||
Underweight | 0.7 | 485 | 0.6 | 108 | 0.7 | 280 | 0.9 | 91 | 2.7 | 6 | ||
Normal weight | 31.0 | 21,498 | 39.6 | 7066 | 28.9 | 12,008 | 24.3 | 2371 | 24.2 | 53 | ||
Overweight | 44.3 | 30,694 | 46.2 | 8230 | 45.2 | 18,761 | 37.1 | 3621 | 37.4 | 82 | ||
Obese class I | 18.5 | 12,806 | 12.0 | 2144 | 20.0 | 8291 | 23.8 | 2323 | 21.9 | 48 | ||
Obese class II | 4.6 | 3168 | 1.3 | 231 | 4.5 | 1859 | 10.8 | 1056 | 10.0 | 22 | ||
Obese class III | 0.9 | 639 | 0.2 | 43 | 0.7 | 293 | 3.0 | 295 | 3.7 | 8 | ||
Diagnosis | 0.001 | 0.037 | ||||||||||
Primary OAb | 92.6 | 64,142 | 92.2 | 16,426 | 93.2 | 38,687 | 90.6 | 8838 | 87.2 | 191 | ||
Otherc | 7.4 | 5148 | 7.8 | 1396 | 6.8 | 2805 | 9.4 | 919 | 12.8 | 28 | ||
Side of operation | 0.001 | 0.016 | ||||||||||
Right | 55.7 | 38,623 | 54.4 | 9692 | 56.2 | 23,330 | 56.2 | 5482 | 54.3 | 119 | ||
Left | 44.3 | 30,667 | 45.6 | 8130 | 43.8 | 18,162 | 43.8 | 4275 | 45.7 | 100 |
Reported problems in the EQ-5D-3L dimensions by ASA class
Patient-reported EQ VAS score
Mean EQ-5D index
Discriminative abilities of value sets among ASA classes
Follow-up | Value sets | ||||||||
---|---|---|---|---|---|---|---|---|---|
Swedish VAS | German VAS | Danisha VAS | UKa VAS | Swedish TTO | Germana TTO | Danisha TTO | UKa TTO | ||
Preoperative | |||||||||
Mean | Overall | 0.54 | 0.49 | 0.44 | 0.49 | 0.73 | 0.54 | 0.54 | 0.42 |
Class I | 0.56 | 0.51 | 0.46 | 0.52 | 0.75 | 0.58 | 0.58 | 0.46 | |
Class II | 0.54 | 0.49 | 0.44 | 0.49 | 0.73 | 0.54 | 0.54 | 0.42 | |
Class III | 0.50 | 0.46 | 0.40 | 0.44 | 0.70 | 0.48 | 0.49 | 0.34 | |
Class IV | 0.46 | 0.42 | 0.36 | 0.38 | 0.67 | 0.40 | 0.41 | 0.25 | |
Effect size [Eta squared (η2)] | 0.015 | 0.014 | 0.019 | 0.015 | 0.016 | 0.012 | 0.015 | 0.014 | |
P-value | < 0.001 | < 0.001 | < 0.001 | < 0.001 | < 0.001 | < 0.001 | < 0.001 | < 0.001 | |
1-year postoperative | |||||||||
Mean | Overall | 0.75 | 0.73 | 0.72 | 0.78 | 0.88 | 0.86 | 0.82 | 0.79 |
Class I | 0.80 | 0.77 | 0.79 | 0.84 | 0.91 | 0.90 | 0.87 | 0.85 | |
Class II | 0.75 | 0.72 | 0.71 | 0.78 | 0.88 | 0.86 | 0.82 | 0.79 | |
Class III | 0.69 | 0.66 | 0.62 | 0.70 | 0.84 | 0.80 | 0.76 | 0.71 | |
Class IV | 0.66 | 0.63 | 0.58 | 0.67 | 0.81 | 0.77 | 0.72 | 0.67 | |
Effect size [Eta squared (η2)] | 0.043 | 0.042 | 0.044 | 0.040 | 0.043 | 0.032 | 0.037 | 0.035 | |
P-value | < 0.001 | < 0.001 | < 0.001 | < 0.001 | < 0.001 | < 0.001 | < 0.001 | < 0.001 |
Predictive effects of ASA class on HRQoL score
Model components | Model estimates | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Patient-reported EQ VAS | Swedish VAS | German VAS | Danish VASb | UK VASb | ||||||
β | RSEa | β | RSEa | β | RSEa | Β | RSEa | β | RSEa | |
Intercept | 0.594* | 0.0017 | 0.562* | 0.0011 | 0.510* | 0.0010 | 0.461* | 0.0010 | 0.520* | 0.0014 |
ASA class II | −0.038* | 0.0020 | −0.024* | 0.0014 | − 0.022* | 0.0012 | −0.024* | 0.0012 | −0.030* | 0.0017 |
ASA class III | −0.084* | 0.0028 | −0.060* | 0.0019 | −0.053* | 0.0018 | −0.061* | 0.0017 | −0.078* | 0.0025 |
ASA class IV | −0.125* | 0.0151 | −0.099* | 0.0100 | −0.088* | 0.0095 | −0.102* | 0.0104 | − 0.138* | 0.0135 |
R2 | 0.0138 | 0.0145 | 0.0136 | 0.0188 | 0.0154 | |||||
MAE | 0.184 | 0.129 | 0.117 | 0.108 | 0.179 | |||||
Normalized MAE | 0.184 | 0.180 | 0.165 | 0.092 | 0.167 | |||||
RMSE | 0.222 | 0.153 | 0.140 | 0.138 | 0.195 | |||||
Normalized RMSE | 0.222 | 0.214 | 0.197 | 0.108 | 0.182 | |||||
Spearman Rank correlation | 0.129 | 0.112 | 0.162 | 0.132 | 0.125 | |||||
Model components | Swedish TTO | German TTOb | Danish TTOb | UK TTOb | ||||||
β | RSEa | β | RSEa | β | RSEa | Β | RSEa | |||
Intercept | 0.749* | 0.0008 | 0.581* | 0.0020 | 0.577* | 0.0016 | 0.460* | 0.0023 | ||
ASA class II | −0.018* | 0.0010 | −0.038* | 0.0025 | −0.033* | 0.0020 | −0.045* | 0.0027 | ||
ASA class III | −0.046* | 0.0014 | −0.098* | 0.0035 | −0.089* | 0.0030 | −0.118* | 0.0039 | ||
ASA Class IV | −0.079* | 0.0079 | −0.179* | 0.0190 | −0.163* | 0.0174 | −0.213* | 0.0215 | ||
R2 | 0.0156 | 0.0119 | 0.0150 | 0.0138 | ||||||
MAE | 0.094 | 0.269 | 0.201 | 0.293 | ||||||
Normalized MAE | 0.149 | 0.223 | 0.124 | 0.184 | ||||||
RMSE | 0.114 | 0.278 | 0.227 | 0.311 | ||||||
Normalized RMSE | 0.181 | 0.231 | 0.140 | 0.195 | ||||||
Spearman Rank correlation | 0.114 | 0.125 | 0.141 | 0.116 |
Model components | Model estimates | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Patient-reported EQ VAS | Swedish VAS | German VAS | Danish VASb | UK VASb | ||||||
β | RSEa | β | RSEa | β | RSEa | β | RSEa | β | RSEa | |
Intercept | 0.824* | 0.0013 | 0.795* | 0.0010 | 0.773* | 0.0011 | 0.790* | 0.0012 | 0.838* | 0.0014 |
ASA class II | −0.062* | 0.0016 | −0.044* | 0.0012 | −0.050* | 0.0014 | −0.076* | 0.0015 | −0.060* | 0.0017 |
ASA class III | −0.140* | 0.0025 | −0.104* | 0.0020 | −0.112* | 0.0021 | −0.165* | 0.0024 | −0.132* | 0.0026 |
ASA Class IV | −0.175* | 0.0148 | −0.138* | 0.0119 | − 0.145* | 0.0121 | −0.213* | 0.0142 | −0.170* | 0.0150 |
R2 | 0.0474 | 0.0430 | 0.0423 | 0.0444 | 0.0402 | |||||
MAE | 0.153 | 0.122 | 0.138 | 0.207 | 0.162 | |||||
Normalized MAE | 0.153 | 0.170 | 0.194 | 0.178 | 0.151 | |||||
RMSE | 0.194 | 0.151 | 0.165 | 0.237 | 0.200 | |||||
Normalized RMSE | 0.194 | 0.211 | 0.232 | 0.203 | 0.186 | |||||
Spearman Rank correlation | 0.288 | 0.275 | 0.205 | 0.236 | 0.177 | |||||
Model components | Swedish TTO | German TTOb | Danish TTOb | UK TTOb | ||||||
β | RSEa | β | RSEa | β | RSEa | β | RSEa | |||
Intercept | 0.909* | 0.0007 | 0.903* | 0.0011 | 0.870* | 0.0012 | 0.848* | 0.0015 | ||
ASA class II | −0.030* | 0.0009 | −0.046* | 0.0014 | −0.051* | 0.0015 | −0.062* | 0.0019 | ||
ASA class III | −0.073* | 0.0014 | −0.105* | 0.0024 | −0.115* | 0.0024 | −0.141* | 0.0031 | ||
ASA Class IV | − 0.100* | 0.0085 | − 0.133* | 0.0152 | − 0.147* | 0.0142 | −0.181* | 0.0186 | ||
R2 | 0.0431 | 0.0318 | 0.0367 | 0.0348 | ||||||
MAE | 0.084 | 0.121 | 0.134 | 0.164 | ||||||
Normalized MAE | 0.133 | 0.101 | 0.083 | 0.111 | ||||||
RMSE | 0.106 | 0.179 | 0.182 | 0.229 | ||||||
Normalized RMSE | 0.169 | 0.148 | 0.112 | 0.247 | ||||||
Spearman Rank correlation | 0.164 | 0.124 | 0.156 | 0.187 |
Model components | Value sets/EQ VAS | ||||||||
---|---|---|---|---|---|---|---|---|---|
Patient-reported EQ VAS | Swedish VAS | German VAS | Danish VASh | UK VASh | Swedish TTO | German TTOh | Danish TTOh | UK TTOh | |
Intercept | 0.860*** | 0.834*** | 0.834*** | 0.880*** | 0.903*** | 0.932*** | 0.952*** | 0.917*** | 0.907*** |
ASA class a | |||||||||
Class II | −0.028*** | −0.015*** | − 0.015*** | − 0.024*** | − 0.020*** | − 0.010*** | − 0.015*** | − 0.018*** | − 0.022*** |
Class III | − 0.066*** | − 0.040*** | − 0.037*** | −0.054*** | − 0.047*** | −0.029*** | − 0.038*** | −0.043*** | − 0.054*** |
Class IV | −0.092*** | − 0.066*** | −0.060*** | − 0.087*** | −0.074*** | − 0.051*** | −0.060*** | − 0.068*** | −0.084*** |
Age group b | |||||||||
50–59 | 0.011*** | 0.010*** | 0.006** | 0.012** | 0.009** | 0.007*** | 0.004 | 0.010*** | 0.010** |
60–69 | 0.029*** | 0.021*** | 0.015*** | 0.019*** | 0.019*** | 0.016*** | 0.013*** | 0.022*** | 0.026*** |
70–79 | 0.021*** | 0.020*** | 0.013*** | 0.013*** | 0.017*** | 0.016*** | 0.013*** | 0.022*** | 0.026*** |
80–98 | −0.006 | 0.002 | −0.004 | −0.020*** | − 0.005 | 0.002 | − 0.001 | 0.005 | 0.006*** |
Sex c | |||||||||
Female | −0.010*** | −0.018*** | − 0.020*** | −0.030*** | − 0.024*** | −0.012*** | − 0.017*** | −0.022*** | − 0.025*** |
BMI category d | |||||||||
Normal weight | 0.025*** | 0.024*** | 0.021*** | 0.034*** | 0.029*** | 0.018*** | 0.022*** | 0.027*** | 0.032*** |
Overweight | 0.026*** | 0.024*** | 0.020*** | 0.033*** | 0.028*** | 0.017*** | 0.020** | 0.026*** | 0.032*** |
Obese class I | 0.018* | 0.017** | 0.012* | 0.021** | 0.019** | 0.012** | 0.011 | 0.019** | 0.022** |
Obese class II | 0.009 | 0.012* | 0.008 | 0.014 | 0.013 | 0.008* | 0.003 | 0.014* | 0.015 |
Obese class III | −0.007 | −0.005 | −0.007 | −0.003 | −0.003 | −0.005 | −0.011 | − 0.003 | −0.005 |
Laterality e | |||||||||
Left | −0.001 | −0.002 | − 0.002 | −0.002 | − 0.001 | −0.001 | 0.0001 | −0.001 | − 0.0006 |
Charnley class f | |||||||||
Class B | − 0.063*** | −0.053*** | − 0.073*** | −0.126*** | − 0.097*** | −0.033*** | − 0.062*** | −0.075*** | − 0.091*** |
Class C | −0.157*** | − 0.146*** | −0.173*** | − 0.256*** | −0.199*** | − 0.098*** | −0.149*** | − 0.166*** | −0.202*** |
Hip pain level g | |||||||||
Very mild | −0.085*** | −0.073*** | − 0.093*** | −0.143*** | − 0.106*** | −0.048*** | − 0.063*** | −0.084*** | − 0.100*** |
Mild | −0.167*** | − 0.138*** | −0.150*** | − 0.194*** | −0.156*** | − 0.096*** | −0.120*** | − 0.138*** | −0.171*** |
Moderate | −0.285*** | −0.257*** | − 0.259*** | −0.278*** | − 0.319*** | −0.184*** | − 0.366*** | −0.342*** | − 0.447*** |
Severe | −0.372*** | − 0.331*** | −0.317*** | − 0.346*** | −0.414*** | − 0.254*** | −0.498*** | − 0.511*** | −0.621*** |
Adjusted R2 | 0.360 | 0.460 | 0.503 | 0.486 | 0.455 | 0.441 | 0.384 | 0.431 | 0.415 |
MAE | 0.121 | 0.083 | 0.092 | 0.143 | 0.117 | 0.058 | 0.088 | 0.100 | 0.123 |
Normalized MAE | 0.121 | 0.116 | 0.129 | 0.123 | 0.109 | 0.092 | 0.073 | 0.062 | 0.077 |
RMSE | 0.159 | 0.114 | 0.119 | 0.174 | 0.151 | 0.081 | 0.143 | 0.140 | 0.178 |
Normalized RMSE | 0.159 | 0.159 | 0.167 | 0.149 | 0.140 | 0.129 | 0.118 | 0.086 | 0.112 |
Spearman’s Rank correlation | 0.598 | 0.683 | 0.701 | 0.696 | 0.692 | 0.688 | 0.687 | 0.679 | 0.682 |