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Table 1 Estimated regression coefficients and standard errors (SE) of data with no values missing; when values are missing completely at random; when outcome blood pressure (BP) is missing at random; when covariate (baseline BP) is missing at random; and when outcome BP is missing not at random

From: When and how should multiple imputation be used for handling missing data in randomised clinical trials – a practical guide with flowcharts

Type of missingness

Randomised groups

Systolic blood pressure

(mmHg) at baseline

mean (SE) N

Systolic blood pressure

(mmHg) at end of trial

mean (SE) N

Parameters

Intercept

estimate

(SE)

P

Baseline blood pressure

estimate

(SE)

P

Intervention

estimate

(SE)

P

None

Experimental

N = 103

181.6 (2.90) N = 103

130.8 (3.17) N = 103

−2.48

(4.69)

P = 0.60

1.013

(0.025)

P < 0.0001

−50.8

(1.48)

P < 0.0001

Control

N = 97

180.9 (2.98)

N = 97

180.9 (3.13) N = 97

MCAR

Experimental

N = 103

181.6 (3.64) N = 74

131.0 (4.02) N = 74

−6.85

(5.22)

P = 0.19

1.041

(0.028)

P < 0.0001

−51.2

(1.69)

P < 0.0001

Control

N = 97

181.8 (3.43) N = 75

182.3 (3.71) N = 75

MAR

(outcome missing)

Experimental

N = 103

181.6 (2.90) N = 103

129.7 (3.97) N = 72

−2.75

(5.13)

P = 0.59

1.015

(0.028)

P < 0.0001

−51.2

(1.66)

P < 0.0001

Control

N = 97

181.0 (2.98) N = 97

180.9 (3.13) N = 97

MAR

(baseline missing)

Experimental

N = 103

181.6 (2.90) N = 103

130.8 (3.17) N = 103

−5.32

(5.56)

P = 0.34

1.004

(0.034)

P < 0.0001

−46.2

(2.22)

P < 0.0001

Control

N = 97

156.2 (2.82) N = 36

180.9 (3.13) N = 97

MNAR

(outcome missing)

Experimental

N = 103

181.6 (2.90) N = 103

127.8 (3.24) N = 95

−8.13

(5.67)

P = 0.15

1.026

(0.032)

P < 0.0001

−47.6

(2.12)

P < 0.0001

Control

N = 97

181.0 (2.98) N = 97

163.4 (5.37) N = 38

  1. The analyses used in all scenarios were a complete case analysis