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Table 1 Baseline characteristics of study population by treatment groups in mail and telephone randomized trials

From: Personalized contact strategies and predictors of time to survey completion: analysis of two sequential randomized trials

 

Mail trial

Telephone trial

Characteristics1

All participants (N = 332)

Personalized envelope (N = 166)

Business envelope (N = 166)

All participants (N = 171)

Study name in message (N = 86)

P.I. name in message (N = 85)

Participant demographics and last contact

      

Age, mean (SD)

48.8 (15.0)

48.2 (15.4)

49.4 (14.7)

46.0 (14.7)

46.7 (14.0)

45.3 (15.5)

Male, n (%)

160 (48)

77 (46)

83 (50)

84 (49)

44 (51)

40 (47)

Minority2, n (%)

64 (20)

27 (17)

37 (23)

42 (26)

19 (23)

23 (28)

Employment status3

      

Employed (full- or part-time), n (%)

97 (30)

41 (25)

56 (34)

52 (31)

32 (38)

20 (24)

Unemployed, n (%)

79 (24)

43 (26)

36 (22)

43 (26)

15 (18)

28 (34)

Retired or disabled, n (%)

151 (46)

80 (49)

71 (44)

72 (43)

37 (44)

35 (42)

Months since last contact, mean (SD)

33.7 (7.3)

34.2 (7.2)

33.3 (7.4)

33.5 (7.5)

35.2 (7.1)

31.7 (7.5)

Physical and mental health status 3 , mean (SD)

      

FPI overall score

2.0 (0.7)

2.0 (0.7)

2.0 (0.7)

1.9 (0.7)

1.9 (0.8)

2.0 (0.7)

FPI body care subscale score

2.5 (0.6)

2.5 (0.6)

2.5 (0.6)

2.5 (0.7)

2.4 (0.7)

2.6 (0.6)

FPI maintaining household subscale score

1.9 (0.9)

1.9 (0.9)

1.9 (0.9)

1.9 (0.9)

1.8 (1.0)

1.9 (0.8)

FPI physical exercise subscale score

1.6 (0.9)

1.6 (0.9)

1.7 (0.9)

1.6 (0.9)

1.6 (1.0)

1.6 (0.9)

SF-36 Physical Component Summary

40.5 (12.5)

40.7 (12.4)

40.3 (12.7)

40.5 (12.8)

40.0 (13.3)

41.1 (12.3)

SF-36 Mental Component Summary

44.9 (14.8)

45.0 (14.4)

44.6 (15.2)

42.1 (14.8)

41.4 (14.3)

42.9 (15.3)

EQ-5D visual analogue scale

69.1 (22.7)

70.3 (22.3)

67.9 (23.0)

67.4 (23.7)

65.5 (24.2)

69.2 (23.3)

EQ-5D utility score

0.7 (0.2)

0.7 (0.2)

0.7 (0.2)

0.7 (0.3)

0.7 (0.3)

0.7 (0.2)

MMSE score

25.6 (1.9)

25.5 (2.0)

25.7 (1.8)

25.5 (2.2)

25.4 (2.6)

25.6 (1.7)

HADS-depression subscale score

6.0 (4.9)

5.9 (4.9)

6.2 (5.0)

6.7 (4.9)

6.8 (5.1)

6.6 (4.7)

HADS-anxiety subscale score

7.0 (5.1)

7.0 (5.3)

7.1 (4.9)

8.0 (5.0)

7.9 (4.7)

8.0 (5.2)

IES-R score

1.0 (1.0)

1.0 (1.0)

1.0 (1.0)

1.1 (1.0)

1.1 (1.0)

1.2 (1.0)

FACIT score

62.3 (18.6)

62.3 (20.0)

62.2 (17.1)

60.2 (16.9)

59.4 (15.6)

61.1 (18.0)

  1. Abbreviations:SD (Standard Deviation), FPI (Functional Performance Inventory), SF-36 (Short Form-36 Health Survey), EQ-5D (EuroQol Five Dimensions Questionnaire), MMSE (Mini-Mental State Examination), HADS (Hospital Anxiety and Depression Scale), IES-R (Impact of Event Scale-Revised), FACIT (Functional Assessment of Chronic Illness Therapy).
  2. 1Missing values for each variable: months since last contact (1, 1), white (12, 7), employment (5, 4), all FPI scores (10, 7), SF-36 Physical and Mental Component Summaries (17, 10), EQ-5D VAS (10, 7), EQ-5D utility (9, 6), MMSE (20, 12), HADS subscales (14, 9), IES-R (16, 11), FACIT (16, 10).
  3. 2Minority race includes African American, Asian, American Indian and Alaskan Native.
  4. 3Status as at last contact with research participant.
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BMC Medical Research Methodology

ISSN: 1471-2288

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