Table 1.

Results of sensitivity analysis (N₉₄ and N₉₉ shows the size of the cohorts of respective years)

	Females				Males
	N₉₄,N₉₉	log-rank	Median (years)		N₉₄,N₉₉	log-rank	Median (years)
			94–96	99–01			94–96	99–01
Base calculation	261,206	0.0009	0.64	0.29	142,115	0.8132	0.39	0.17
1. Approaches to identification of recovery events
Time to recovery (1.5 years)	237,192	0.0049	1.05	0.36	135,109	0.9988	0.69	0.41
Time to recovery (0.5 years)	286,223	0.0043	0.34	0.21	155,129	0.9686	0.24	0.17
Alzheimer’s disease and dementia	261,206	0.0178	0.61	0.41	142,115	0.4345	0.42	0.17
2. Approaches to identification of incident cases
All Medicare sources used	286,221	0.0013	0.64	0.31	159,125	0.6977	0.39	0.24
Keeping not only primary diagnoses	323,269	0.0009	0.49	0.24	182,145	0.4876	0.36	0.09
No requirement of second visit	523,416	0.0111	0.09	0.05	276,242	0.4220	0.05	0.01
Acceptable lag of pre-diagn.=0.5year	261,206	0.0009	0.64	0.29	146,117	0.8363	0.39	0.20
Only 436 ICD-9 code included	228,182	0.0017	0.61	0.25	123,90	0.8276	0.39	0.24
Exclude hemorrhagic (ie, 431) stroke	258,202	0.0016	0.62	0.29	141,109	0.7406	0.39	0.25
Only hemorrhagic (i.e., 431) stroke	13,14	0.5680	0.016	0.063	10,12	0.1711	0.227	0.027
Include ICDs: 430–432	23,28	0.0871	0.112	0.067	20,20	0.6478	0.153	0.114
Exclude not completely covered	229,188	0.0041	0.61	0.27	136,108	0.5108	0.39	0.14
3. Factors of observed heterogeneity
65≤Age≤72	56,43	0.0140	0.61	0.21	31,31	0.4543	0.25	0.32
73≤Age≤84	139,110	0.0096	0.72	0.30	95,66	0.8493	0.39	0.20
85≤Age	66,53	0.4828	0.61	0.46	16,18	0.3374	0.15	0.09
Charlson Index=0	107,77	0.0522	0.61	0.24	55,36	0.9565	0.18	0.23
1≤Charlson Index≤3	120,95	0.0232	0.76	0.36	66,56	0.7897	0.46	0.14
Charlson Index≥4	34,34	0.1317	0.61	0.25	21,23	0.8836	0.79	0.25
Disability group=1	143,128	0.0007	0.60	0.24	97,87	0.4733	0.39	0.13
Disability group=2	47,27	0.0504	1.01	0.21	22,13	0.4767	0.13	0.28
Disability group=3	71,51	0.9775	0.80	0.90	23,15	0.5246	1.32	1.49
4. Censoring strategies
Cases of death are recovery cases	261,206	0.0059	0.50	0.25	142,115	0.4704	0.39	0.16
Cases of death are never recovered	346,278	0.0478	2.61	0.93	194,154	0.5400	1.20	1.17
5. Disenrollment from Medicare and coverage by HMO
All covered by HMO are included	284,215	0.0125	0.61	0.33	149,124	0.8593	0.37	0.17
Fraction of HMO enrollment≤0.3	264,209	0.0015	0.62	0.31	145,118	0.9811	0.39	0.17
6. Study Design effect
Using NLTCS weights	472524, 427500		0.62	0.31	270628, 255493		0.39	0.13