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
| 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 | ||||
The analyses used in all scenarios were a complete case analysis