Table 3.

Characteristics of the Overall Sample and the Two Groups of Participants With the Low- and Normative Performance Profiles in the Maintenance of Balance, Independent Living, Intellect, and Zest in the Elderly of Boston Study

	Total Sample	Low-Performance Group	Normative Performance Group	p Value
n (%)	580	99 (17)	459 (79)
Age, y	77.8 ± 0.2	79.9 ± 0.6	77.3 ± 0.2	<.0001
Gender (% women)	64	67	63	.53
Race, %
African American	14	36	9	<.0001
Other	6	8	5
Body mass index, kg/m2	27.3 ± 0.2	27.8 ± 0.5	27.1 ± 0.2	.19
No physician, %	3	3	3	.99
Smoking, %
Current	4	2	4	.04
Past	52	43	55
Alcohol (% none or <2 drinks per day)	93	98	91	.02
Education, % <12 y	9	32	3	<.0001
Self-reported comorbid illnesses, %
Arthritis	45	42	44	.72
Kidney disease	6	9	5	.39
Anemia	21	20	20	.75
Cancer	23	21	23	.45
Depression	17	16	15	.88
Spinal stenosis or disc disease	20	14	21	.212
Parkinson's disease	1	1	1	.94
Overall health (% fair to poor)	14	31	8	<.0001
Cognitive function
Mini-Mental State Examination	27.2 ± 0.1	24.3 ± 0.3	27.9 ± 0.1	<.0001
HVLT, overall z score	NA*	−0.6 ± 0.1	0.2 ± 0.1	<.0001
HVLT, recognition z score (pure memory test)	NA*	−0.7 ± 0.1	0.3 ± 0.1	<.0001
TMT-B (adjusted for motor speed using TMT-A)	88.2 ± 3.2	195.5 ± 5.9	60.7 ± 1.8	<.0001
TMT-B adjusted for trail A, z score	NA†	1.2 ± 0.1	−0.4 ± 0.1	<.0001
Functional measures
Activities of daily living (% no impairment)	81	67	84	<.0001
Instrumental activities of daily living (% no impairment)	61	49	66	<.003
Short Physical Performance Battery	9.1 ± 0.1	8.1 ± 0.2	9.3 ± 0.1	<.0001
Pain interfere with walking, %
No	46	43	47	.67
Mild	39	43	37

Notes: HVLT = Hopkins Verbal Learning Test; TMT = Trail Making Test.

^*This measure was standardized to an M of 0 and SD of 1.

^†Total sample = 580 includes the two small groups of the four-class solution.