. 2008 May 7;33(3):643–651. doi: 10.1007/s00264-008-0549-4

Table 1.

Changes in the prevalence of characteristics of discharges with the diagnosis for total hip arthroplasty by period of interest (POI) from 1990–2004

Primary hip arthroplasties (ICD-9 81.51), 1990–2004, N =2,288,579
Period	1990–1994		1995–1999		2000–2004		1990–2004
N (% of total)	603,528	26.37	731921	31.98	953,130	41.65	2,288,579	100.00
Age in years (range)^a	67.03 (6–99)		67.19 (13–99)		66.08 (18–99)		66.68 (6–99)
Age groups
<45^a (POI1 and 2 and POI1 and 3 only)	49,716	8.24	48,907	6.68	64,336	6.75	162,959	7.12
46–64^a	149,393	24.75	198,905	27.18	326,889	34.30	675,187	29.50
65–79^a(POI1 and 3 and POI2 and 3 only)	365,940	60.63	443,428	60.58	512,862	53.81	1,322,230	57.78
85+^a	38,479	6.38	40,681	5.56	49,043	5.15	128,203	5.60
Gender^b
Male^a	243,495	40.35	303,583	41.48	408,303	42.84	955,381	41.75
Female^a	360,033	59.66	428,338	58.52	544,827	57.16	1,333,198	58.25
Race*
White^a	452,691	75.01	501,914	68.58	628,157	65.91	1,582,762	69.16
Black^a	24,298	4.03	38,022	5.20	50,574	5.31	112,894	4.93
Other^a	10,296	1.71	13,369	1.83	13,496	1.42	37,161	1.62
Not stated^a	11,6243	19.26	178,616	24.40	260,903	27.37	555,762	24.28
Discharge status^b
Routine discharge to home^a	375,775	62.26	348,626	47.63	423,627	44.45	1,148,028	50.16
Left against medical advice^a(POI1 and 2 and POI1 and 3 only)	1,614	0.27	120	0.02	168	0.02	1,902	0.08
Discharge to short-term facility^a	39,737	6.58	68,572	9.37	96,170	10.09	204,479	8.94
Discharge to long-term facility^a (POI1 and 2 and POI 1 and 3 only)	97,139	16.10	181,079	24.74	235,263	24.68	513,481	22.44
Alive disposition not stated^a	77,437	12.83	122,529	16.74	170,369	17.88	370,335	16.18
Dead^a (POI 1 and 3 and POI 2 and 3 only)	1,977	0.33	2,446	0.33	2,839	0.30	7,262	0.32
Not stated or reported^a	9,849	1.63	8,549	1.17	24,694	2.59	43,092	1.88
Bed size^b
6–99^a	74,520	12.35	114,748	15.68	242,868	25.48	432,136	18.88
100–199^a	154,988	25.68	197,771	27.02	228,501	23.97	581,260	25.40
200–299^a	134,831	22.34	146,871	20.07	194,213	20.38	475,915	20.80
300–499^a	172,922	28.65	190,649	26.05	182,937	19.19	546,508	23.88
500+^a (POI1 and 2 and POI2 and 3 only)	66,267	10.98	81,882	11.19	104,611	10.98	252,760	11.04
Region^b
Northeast^a	133,397	22.10	159,541	21.80	232,522	24.40	525,460	22.96
Midwest^a	172,362	28.56	201,757	27.57	256,897	26.95	631,016	27.57
Southern^a	177,790	29.46	213,484	29.17	289,605	30.39	680,879	29.75
Western^a	119,979	19.88	157,139	21.47	174,106	18.27	451,224	19.72
Insurance^b
Medicare^a	377,515	62.55	434,217	59.33	409,861	43.00	1,221,593	53.38
Medicaid^a	16,690	2.77	24,135	3.30	29,507	3.10	70,332	3.07
Private^a	159,214	26.38	233,905	31.96	311,526	32.69	704,645	30.79
Other^a	35,718	5.92	35,024	4.79	197,663	20.74	268,405	11.73
Not stated^a	14,391	2.38	4,640	0.63	4,573	0.48	23,604	1.03
Length of care in days (range)^c	8.74 (1–315)		5.17 (1–170)		4.45 (1–312)		5.81 (1–315)

POI period of interest, POI1 = 1990–1994, POI2 = 1995–1999, POI3 = 2000–2004

^a Significant differences found between all POIs (or POIs specified in parentheses) within variable using Z-score

^b Significant differences found across categories within variable using chi square test

^c Significant differences between POI using general linear model