Table 3.
Associations between the length of stay and IHI according to disease.
| Spondylosis | Back pain | Sprain and strain | Intervertebral disc disorders | Fracture | |||||||||||
| Parameter | Estimate | SE | Pr > t | Estimate | SE | Pr > t | Estimate | SE | Pr > t | Estimate | SE | Pr > t | Estimate | SE | Pr > t |
| IHI | −0.019 | 0.01 | 0.001 | 0.020 | 0.01 | 0.009 | 0.033 | 0.01 | <0.0001 | −0.029 | 0.00 | <0.0001 | −0.095 | 0.01 | <0.0001 |
| IHI (quadratic) | 0.002 | 0.00 | 0.003 | −0.002 | 0.00 | 0.016 | −0.003 | 0.00 | <0.0001 | 0.003 | 0.00 | <0.0001 | 0.010 | 0.00 | <0.0001 |
| ln (total expense) | 0.724 | 0.00 | <0.0001 | 0.798 | 0.01 | <0.0001 | 0.815 | 0.01 | <0.0001 | 0.735 | 0.00 | <0.0001 | 0.940 | 0.01 | <0.0001 |
| Sex | |||||||||||||||
| Male | ref. | ref. | ref. | ref. | ref. | ||||||||||
| Female | 0.013 | 0.01 | 0.051 | 0.011 | 0.01 | 0.151 | 0.017 | 0.01 | 0.013 | 0.035 | 0.00 | <0.0001 | 0.030 | 0.01 | 0.013 |
| Age | |||||||||||||||
| Under 40 | ref. | ref. | ref. | ref. | ref. | ||||||||||
| 40–64 | 0.025 | 0.02 | 0.1442 | 0.005 | 0.01 | 0.5792 | 0.002 | 0.01 | 0.7552 | −0.018 | 0.00 | 0.0002 | 0.008 | 0.03 | 0.76 |
| ≥65 | 0.014 | 0.02 | 0.4346 | 0.009 | 0.01 | 0.5026 | −0.015 | 0.01 | 0.1935 | −0.036 | 0.01 | <0.0001 | −0.111 | 0.03 | <0.0001 |
| Comorbidity level (CCI)† | |||||||||||||||
| Minor (CCI ≤ 1) | ref. | ref. | ref. | ref. | ref. | ||||||||||
| Moderate (CCI = 2) | 0.005 | 0.01 | 0.605 | −0.010 | 0.01 | 0.464 | −0.003 | 0.01 | 0.801 | 0.010 | 0.01 | 0.172 | −0.007 | 0.01 | 0.628 |
| Severe (CCI ≥ 3) | 0.006 | 0.01 | 0.4575 | −0.005 | 0.01 | 0.6122 | 0.010 | 0.01 | 0.3115 | 0.006 | 0.01 | 0.3121 | −0.004 | 0.01 | 0.74 |
| Insurance type | |||||||||||||||
| Medicare | ref. | ref. | ref. | ref. | ref. | ||||||||||
| NHI | −0.137 | 0.01 | <0.0001 | −0.155 | 0.01 | <0.0001 | −0.130 | 0.01 | <0.0001 | −0.151 | 0.01 | <0.0001 | −0.088 | 0.02 | <0.0001 |
| Surgery | |||||||||||||||
| No | ref. | ref. | ref. | ref. | ref. | ||||||||||
| Yes | −0.309 | 0.01 | <0.0001 | −0.394 | 0.03 | <0.0001 | −0.366 | 0.03 | <0.0001 | −0.281 | 0.01 | <0.0001 | −0.428 | 0.01 | <0.0001 |
| Hospital type | |||||||||||||||
| Tertiary general hospital | ref. | ref. | ref. | ref. | ref. | ||||||||||
| General hospital | 0.229 | 0.01 | <0.0001 | 0.096 | 0.02 | <0.0001 | −0.030 | 0.05 | 0.5642 | 0.114 | 0.01 | <0.0001 | 0.249 | 0.03 | <0.0001 |
| Western hospital | 0.368 | 0.02 | <0.0001 | 0.319 | 0.03 | <0.0001 | 0.172 | 0.05 | 0.0014 | 0.346 | 0.02 | <0.0001 | 0.369 | 0.03 | <0.0001 |
| Traditional hospital | 0.457 | 0.04 | <0.0001 | 0.396 | 0.04 | <0.0001 | 0.132 | 0.06 | 0.0202 | 0.628 | 0.02 | <0.0001 | 0.596 | 0.09 | <0.0001 |
| Bed grade | |||||||||||||||
| Under 100 beds | ref. | ref. | ref. | ref. | ref. | ||||||||||
| 100–300 beds | −0.020 | 0.01 | 0.0235 | −0.027 | 0.01 | 0.056 | −0.083 | 0.01 | <0.0001 | −0.017 | 0.01 | 0.0019 | −0.043 | 0.02 | 0.0119 |
| More than 300 beds | 0.014 | 0.02 | 0.3659 | −0.080 | 0.02 | 0.0003 | −0.101 | 0.02 | <0.0001 | −0.025 | 0.01 | 0.0161 | −0.064 | 0.02 | 0.0059 |
| Region | |||||||||||||||
| Capital city | −0.032 | 0.01 | 0.000 | −0.018 | 0.02 | 0.244 | −0.032 | 0.01 | 0.032 | 0.015 | 0.01 | 0.012 | −0.040 | 0.02 | 0.016 |
| Metropolitan area | 0.012 | 0.01 | 0.1303 | −0.012 | 0.01 | 0.1505 | −0.007 | 0.01 | 0.3643 | 0.024 | 0.00 | <0.0001 | 0.051 | 0.01 | <0.0001 |
| Nonmetropolitan area | ref. | ref. | ref. | ref. | ref. | ||||||||||
| No. of WM doctors per 50 beds | |||||||||||||||
| 0 < n ≤ 3 | ref. | ref. | ref. | ref. | ref. | ||||||||||
| 3 < n ≤ 5 | −0.146 | 0.01 | <0.0001 | −0.171 | 0.02 | <0.0001 | −0.124 | 0.01 | <0.0001 | −0.083 | 0.01 | <0.0001 | −0.059 | 0.02 | 0.0057 |
| 5 < n ≤ 7 | −0.181 | 0.01 | <0.0001 | −0.158 | 0.02 | <0.0001 | −0.158 | 0.02 | <0.0001 | −0.144 | 0.01 | <0.0001 | −0.113 | 0.02 | <0.0001 |
| n > 7 | −0.239 | 0.02 | <0.0001 | −0.265 | 0.02 | <0.0001 | −0.207 | 0.02 | <0.0001 | −0.209 | 0.01 | <0.0001 | −0.174 | 0.03 | <0.0001 |
| No. of TM doctors per 50 beds | |||||||||||||||
| 0 < n ≤ 1 | ref. | ref. | ref. | ref. | ref. | ||||||||||
| 1 < n ≤ 2 | 0.262 | 0.04 | <0.0001 | −0.031 | 0.01 | 0.007 | −0.019 | 0.01 | 0.087 | 0.050 | 0.02 | 0.005 | 0.133 | 0.09 | 0.148 |
| 2 < n ≤ 3 | 0.190 | 0.06 | 0.001 | −0.024 | 0.02 | 0.216 | −0.021 | 0.02 | 0.304 | 0.069 | 0.03 | 0.010 | 0.005 | 0.13 | 0.967 |
| n > 3 | 0.120 | 0.04 | 0.003 | −0.031 | 0.02 | 0.167 | −0.007 | 0.02 | 0.735 | −0.041 | 0.02 | 0.045 | 0.113 | 0.11 | 0.294 |
| No. of nurses per 50 beds | |||||||||||||||
| 0 < n ≤ 7 | ref. | ref. | ref. | ref. | ref. | ||||||||||
| 7 < n ≤ 18 | −0.073 | 0.01 | <0.0001 | −0.128 | 0.02 | <0.0001 | −0.118 | 0.01 | <0.0001 | −0.072 | 0.01 | <0.0001 | −0.114 | 0.02 | <0.0001 |
| 18 < n ≤ 30 | −0.090 | 0.01 | <0.0001 | −0.163 | 0.02 | <0.0001 | −0.195 | 0.02 | <0.0001 | −0.093 | 0.01 | <0.0001 | −0.220 | 0.02 | <0.0001 |
| n > 30 | −0.215 | 0.02 | <0.0001 | −0.232 | 0.03 | <0.0001 | −0.264 | 0.02 | <0.0001 | −0.170 | 0.01 | <0.0001 | −0.361 | 0.03 | <0.0001 |
| Intercept | −7.895 | 0.06 | <0.0001 | −8.715 | 0.08 | <0.0001 | −8.768 | 0.09 | <0.0001 | −8.022 | 0.04 | <0.0001 | −10.789 | 0.11 | <0.0001 |