Supplementing claims data with outpatient laboratory test results to improve confounding adjustment in effectiveness studies of lipid-lowering treatments

Schneeweiss, Sebastian; Rassen, Jeremy A; Glynn, Robert J; Myers, Jessica; Daniel, Gregory W; Singer, Joseph; Solomon, Daniel H; Kim, SeoYoung; Rothman, Kenneth J; Liu, Jun; Avorn, Jerry

doi:10.1186/1471-2288-12-180

Table 3 Patients with lab test results reported in study population of 703,484 initiators of statins or ezetimibe using a 6-month covariate assessment period*

From: Supplementing claims data with outpatient laboratory test results to improve confounding adjustment in effectiveness studies of lipid-lowering treatments

Patient characteristics as determined in CAP	All patients	Patients with at least 1 of any 23 lab tests¹⁾					Patients with at least 1 LDL test					Patients with at least 1 HDL test					Patients with at least 1 Hb_A1c test
		Tests performed		Results available			Tests performed		Results available			Tests performed		Results available			Tests performed		Results available
	N	N	% of total	N	% of total	% of done	N	%	N	%	% of performed	N	%	N	%	% of performed	N	%	N	%	% of performed
All patients	703,484	481,133	68	204,143	29	42	421,708	60	178,254	25	42	417,598	59	176,780	25	42	121,764	17	56,653	8	47
Age
18-40	71,396	52,674	74	23,861	33	45	48,565	68	21,313	30	44	48,021	67	21,150	30	44	12,424	17	5,770	8	46
41-64	489,581	363,406	74	150,096	31	41	329,097	67	131,999	27	40	325,945	67	130,912	27	40	92,076	19	40,635	8	44
65+	142,507	65,053	46	30,186	21	46	44,046	31	24,942	18	57	43,632	31	24,718	17	57	17,264	12	10,248	7	59
Male sex	378,177	256,537	68	107,876	29	42	225,308	60	94,715	25	42	223,007	59	93,962	25	42	66,202	18	30,286	8	46
# of days hospitalized	1	1		1			0	54	0	51	93	0	55	0	51	91	1	91	1	78	86
Hospitalized in 30 days before treatment initiation (y/n)	52,959	29,933	57	8,871	17	30	15,942	30	5,738	11	36	15,929	30	5,691	11	36	6,353	12	2,483	5	39
Hospitalized in 31 to 180 days before treatment initiation (y/n)	39,304	28,823	73	10,569	27	37	18,889	48	7,546	19	40	18,790	48	7,491	19	40	7,852	20	3,405	9	43
Any coronary hospitalization**	43,507	25,909	60	7,468	17	29	13,821	32	4,911	11	36	13,775	32	4,869	11	35	5,545	13	2,100	5	38
# of cardiologist visits	0	0		0			0		0			0		0			0		0
# of other physician visits	3	4		3			3		3			3		3			4		3
Number of different drugs	4	4		4			4		4			4		4			6		5
# of lab tests performed	6	9		7			9		6			9		6			12		8
Vascular conditions:
Hypercholesterolemia	358,649	308,261	86	100,890	28	33	286,144	80	88,027	25	31	282,875	79	87,016	24	31	74,655	21	23,200	6	31
Hypertension	351,542	244,573	70	100,813	29	41	207,406	59	85,722	24	41	205,531	58	84,903	24	41	75,677	22	33,388	9	44
Heart failure	16,008	10,057	63	3,243	20	32	5,082	32	1,917	12	38	5,064	32	1,891	12	37	2,884	18	1,089	7	38
Acute MI	20,797	11,127	54	2,673	13	24	5,074	24	1,709	8	34	5,046	24	1,698	8	34	1,966	9	714	3	36
Old MI	5,166	3,734	72	998	19	27	2,345	45	714	14	30	2,320	45	705	14	30	873	17	293	6	34
Acute coron. syndrome	63,781	40,721	64	12,776	20	31	25,407	40	9,242	14	36	25,206	40	9,155	14	36	9,328	15	3,791	6	41
TIA/stroke	16,747	9,764	58	3,086	18	32	5,731	34	2,098	13	37	5,692	34	2,080	12	37	2,255	13	845	5	37
Carotid revasc³⁾	888	598	67	193	22	32	370	42	134	15	36	369	42	135	15	37	137	15	50	6	36
PVD	8,032	5,489	68	1,868	23	34	3,241	40	1,300	16	40	3,260	41	1,284	16	39	1,515	19	642	8	42
Coronary revasc²⁾	22,575	13,317	59	3,581	16	27	7,098	31	2,377	11	33	7,069	31	2,351	10	33	2,610	12	942	4	36
Peripheral revas	987	748	76	261	26	35	388	39	171	17	44	394	40	170	17	43	204	21	90	9	44
Diabetes	111,684	89,344	80	34,137	31	38	74,576	67	28,032	25	38	73,937	66	27,693	25	37	76,413	68	26,959	24	35
Pre-diabetes	9,916	8,941	90	2,559	26	29	7,957	80	2,032	20	26	7,877	79	2,016	20	26	6,258	63	1,569	16	25
Rheumatoid arthritis	4,523	3,676	81	1,520	34	41	2,650	59	935	21	35	2,620	58	926	20	35	839	19	315	7	38
Recorded obesity	20,533	17,354	85	5,295	26	31	15,138	74	4,307	21	28	14,971	73	4,251	21	28	6,897	34	1,956	10	28
COPD	27,318	18,918	69	6,382	23	34	13,236	48	4,855	18	37	13,144	48	4,818	18	37	4,557	17	1,708	6	37
Use of oxygen tank	105	59	56	20	19	34	41	39	13	12	32	42	40	13	12	31	20	19	8	8	40
Plan type: Indemnity	3,942	3,391	86	807	20	24	3,149	80	696	18	22	3,132	79	698	18	22	823	21	181	5	22
HMO	202,910	109,821	54	100,426	49	91	95,306	47	92,427	46	97	94,360	47	91,683	45	97	28,471	14	30,241	15	106
Medicare Advantage	62,459	37,744	60	24,757	40	66	28,014	45	20,468	33	73	27,758	44	20,304	33	73	11,658	19	8,622	14	74
Medicare Supplemental	43,645	15,519	36	1,294	3	8	7,822	18	1,000	2	13	7,745	18	994	2	13	2,647	6	285	1	11
Other	22,274	10,323	46	4,057	18	39	8,677	39	3,486	16	40	8,593	39	3,456	16	40	2,422	11	1,153	5	48
Preferred Provider Org.	368,254	304,335	83	72,802	20	24	278,740	76	60,177	16	22	276,010	75	59,645	16	22	75,743	21	16,171	4	21
State of residence: 1	194,150	97,286	50	51,523	27	53	83,875	43	46,332	24	55	82,694	43	46,342	24	56	25,050	13	16,146	8	64
2	23,642	20,159	85	9,281	39	46	18,674	79	8,517	36	46	18,678	79	8,521	36	46	5,416	23	2,352	10	43
3†	5,006	3,783	76	359	7	9	3,420	68	318	6	9	3,395	68	311	6	9	923	18	85	2	9
4	64,242	53,997	84	30,197	47	56	49,458	77	27,231	42	55	48,892	76	26,855	42	55	13,198	21	7,569	12	57
5	36,365	29,200	80	4,805	13	16	25,522	70	3,635	10	14	25,903	71	3,604	10	14	6,872	19	917	3	13
6	48,045	37,348	78	8,630	18	23	32,056	67	6,583	14	21	31,752	66	6,476	13	20	8,929	19	1,723	4	19
7	13,847	11,833	85	359	3	3	10,773	78	260	2	2	10,647	77	259	2	2	2,678	19	44	0	2
8	28,450	23,108	81	6,178	22	27	20,781	73	5,309	19	26	20,627	73	5,276	19	26	5,877	21	1,461	5	25
9	8,703	7,401	85	1,089	13	15	6,789	78	875	10	13	6,772	78	886	10	13	1,812	21	243	3	13
10†	3,753	2,464	66	1,183	32	48	2,226	59	1,097	29	49	2,188	58	1,083	29	49	710	19	369	10	52
11	4,864	3,610	74	2,310	47	64	3,217	66	2,030	42	63	3,137	64	2,029	42	65	1,015	21	648	13	64
12	64,237	24,644	38	36,009	56	146	15,190	24	32,988	51	217	14,979	23	32,722	51	218	6,068	9	12,646	20	208
13	85,926	71,455	83	22,481	26	31	63,065	73	18,108	21	29	62,703	73	17,993	21	29	19,587	23	5,464	6	28
Other	44,110	35,064	79	5,628	13	16	31,850	72	4,867	11	15	31,462	71	4,839	11	15	8,949	20	1,446	3	16
14†	3,804	3,311	87	116	3	4	3,113	82	100	3	3	3,107	82	99	3	3	876	23	31	1	4
15	74,340	56,470	76	23,995	32	42	51,699	70	20,004	27	39	50,662	68	19,485	26	38	13,804	19	5,509	7	40

* Study period starts July 1, 2005, ensuring a minimum CAP of 6 months with lab test results coverage and a pre-CAP of 6 months.
** Hospitalization with primary discharge code for acute MI, ACS, PCTA, PCI, CABG.
† States with no WellPoint presence.
1) This is limited to 23 lab test results reported in our study database.
2) PCTA, PCI, CABG.
3) Carotid stent, carotid endarterectomy.

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