External review and validation of the Swedish national inpatient register

Table 2 Comparison between Swedish Quality Registers and the National Patient Register [9]

Disease/ Procedure	Quality Register	Total number of cases	Matching between the Quality Register and the Patient Register (%)	Proportion of all cases identified through the Patient Register (%)
Hernia surgery*	Swedish Hernia Register	17,707	69.9	92.5
Cholecystectomy*	Swedish Register of Gallstone Surgery and ERCP	12,472	79.9	96.4
ERCP*		7,458	54.5	71.2
Multiple Sclerosis*	Swedish Multiple Sclerosis Register	13,503	52.9	76.4
Knee arthroplasty	The Swedish Knee Arthroplasty Register	11,122	90.1	93.6
Hip arthroplasty	The Swedish Hip Arthroplasty Register	14,757	91.0	93.4
Hip fracture	The Swedish Hip Fracture Register	15,920	64.0	95.3
Surgery on the abdominal aorta*	Swedvasc	1,784	77.4	90.6
Infrainguinal bypass surgery		979	72.4	81.9
Carotid artery surgery		1,584	81.6	95.2
First stroke	Swedish Stroke Register	22,202	79.4	96.0
Heart surgery	Swedish Heart Surgery Register#	13,440	95.1	97.6
Cataract surgery*	National Cataract Register	75,050	75.2	78.6
Prostate cancer*	National Prostate Cancer Register	3,985	62.0	82.8

ERCP = endoscopic retrograde cholangiopancreatography
* Quality register compared with the Patient Register (IPR and hospital-based outpatient data). In the other comparisons the Quality Register was compared only with the IPR.
# Currently part of the Register Swedeheart.