Het volume van chirurgische ingrepen en de impact ervan op ... - KCE
Het volume van chirurgische ingrepen en de impact ervan op ... - KCE
Het volume van chirurgische ingrepen en de impact ervan op ... - KCE
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<strong>KCE</strong> Reports 113 Volume Outcome 209<br />
DESCRIPTION OF DIFFERENCES IN CHARACTERISTICS ACCORDING TO<br />
THE VOLUME CATEGORY OF THE HOSPITAL<br />
Table 7.42 shows the case mix and pati<strong>en</strong>t characteristics in function of the <strong>volume</strong><br />
<strong>op</strong>erated by hospital, classified by tertile. Regardless of the tertile, 75% of the pati<strong>en</strong>t<br />
p<strong>op</strong>ulation was female and had a mean age of 79.2 years. Compared with medium- and<br />
high-<strong>volume</strong> hospitals (more than 110 hip fracture surgeries in 2004), pati<strong>en</strong>ts in small<strong>volume</strong><br />
hospitals (less than 60 procedures) had slightly differ<strong>en</strong>t characteristics: there<br />
were more m<strong>en</strong> (29.0%), they were slightly younger (mean age 78.1 years) and they had<br />
a higher severity in<strong>de</strong>x (34.1% with SOI = 3, 7.6% with SOI = 4). Their Charlson in<strong>de</strong>x<br />
score was similar, though.<br />
Table 7.42: Hip fracture surgery: Differ<strong>en</strong>ces in case-mix and outcomes by<br />
<strong>volume</strong> category of hospital<br />
Tertile based on <strong>volume</strong><br />
≤59 >59 and >110<br />
≤96<br />
All<br />
Number hospitals 39 37 37 113<br />
Number stays 1712 2891 5331 9934<br />
Male % 29.0 25.3 24.0 25.3<br />
Age<br />
Mean 78.1 79.1 79.6 79.2<br />
Std 13.0 12.2 11.7 12.1<br />
Charlson in<strong>de</strong>x score<br />
Mean 1.2 1.3 1.2 1.2<br />
Std 1.6 1.7 1.7 1.7<br />
Charlson ≥ 3 % 18.5 19.0 17.1 17.9<br />
Severity in<strong>de</strong>x<br />
(APR-DRG)<br />
1 % 23.8 22.3 21.9 22.3<br />
2 % 34.6 39.6 39.1 38.5<br />
3 % 34.1 30.9 31.7 31.9<br />
4 % 7.6 7.2 7.3 7.3<br />
In-hospital mortality % 6.4 6.3 6.6 6.5<br />
RELATION<br />
MORTALITY<br />
BETWEEN HOSPITAL VOLUME AND IN-HOSPITAL<br />
The results of the logistic regression are pres<strong>en</strong>ted in Table 7.43. There is no significant<br />
association betwe<strong>en</strong> a 10% increase in hospital <strong>volume</strong> and the in-hospital mortality as<br />
the effect was +0.48% (-1.22%, 2.17%), without adjusting for case-mix differ<strong>en</strong>ces. After<br />
adjustm<strong>en</strong>t for case mix, an increase of 1 category Charlson score was translated by a<br />
more than doubling of the in-hospital mortality; the odds ratio being 2.13 (1.99, 2.28).<br />
Being a male gave the same effect (odds for mortality: 1.99; 1.64, 2.40). Both effects<br />
were statistically significant. On the contrary, an increase of 10% of the hospital <strong>volume</strong><br />
still had no significant effect (+0.61%; -1.24%, 2.47%).<br />
Table 7.43: Hip fracture surgery: Correlation-corrected logistic regression<br />
(GEE) estimates of <strong>de</strong>terminants of in-hospital mortality<br />
Mo<strong>de</strong>l without adjustm<strong>en</strong>t for case mix Effect 1 95% CI<br />
Hospital <strong>volume</strong> (increase of 10%) 0.48 -1.22 2.17<br />
Mo<strong>de</strong>l with adjustm<strong>en</strong>t for case mix Effect 1 95% CI<br />
Hospital <strong>volume</strong> (increase of 10%) 0.61 -1.24 2.47<br />
Odds Ratio 95% CI<br />
Sex (male vs. female) 1.99 1.64 2.40<br />
Age (increase of 1 year) 1.06 1.05 1.07<br />
Charlson score (increase of 1 category) 2.13 1.99 2.28<br />
1 Effect of 10% increase in <strong>volume</strong> of hospital on the odds of in-hospital mortality