Table 1.

 Characteristics of study sample

Characteristics	Internal medicine	Internal medicine subspecialty	Family Medicine	Pediatrics	General surgery	Surgical subspecialty	Obstetrics and gynecology
No of physicians	8654	2745	2519	3649	3319	1812	1939
No of physician years	53 984	18 138	13 163	22 820	21 404	11 874	13 342
No of hospital admissions	7 682 304	1 505 529	1 412 864	2 740 541	1 863 745	998 797	2 148 611
No of hospital admissions per physician year	142	83	107	120	87	84	161
No of malpractice claims	1 442	501	246	359	869	385	540
No of malpractice claims per 100 physician years	2.7	2.8	1.9	1.6	4.1	3.2	4.0
Mean adjusted annual charges per hospital admission ($):*
Physicians with a malpractice claim	25 775	30 972	18 653	11 034	31 474	33 561	10 601
Physicians without a malpractice claim	28 636	34 621	22 566	12 689	36 701	40 804	12 656
P value for difference†	<0.001	<0.001	0.02	<0.001	<0.001	<0.001	<0.001

$1.00 (£0.65; €0.88).

*Adjusted for patient age, sex, race, comorbid conditions, diagnosis related group, county fixed effects, and year. Charges for physicians with a malpractice claim reflect the mean hospital charges per physician in the year previous to an incident among physicians with a malpractice claim (that is, cases). Charges for physicians without a malpractice claim reflect the mean hospital charges per physician in all years among physicians with a malpractice claim (that is, controls). The purpose of this case-control comparison was to examine whether hospital charges in the year previous to an incident that led to malpractice (among physicians who faced a malpractice claim) differed from average annual hospital charges for physicians who were not sued.

†Difference in means between cases and controls.