In total, three very preterm children (4.2%) had missing measures of cognitive and motor functioning at 1/2 and 1 year of age.
During the test, the north LVDT rosette missed measuring the tensile strains at the location of first shear crack which appeared out of the studied zone.
Forty-nine children who were missing DAP measures at either the 6-month or 5-year visit, or missing more than one DAP measure from the three other time points, were excluded from the AUC analysis.
Several children were missing DAP measures at 3.5 years (n = 58) and 5 years (n = 14).
Of the 8 remaining participants, 3 (1%), 3 (1%), and 2 (<1%) had missing SBP measures at 2, 3, and 5 time points, respectively.
This approach takes correlations between repeated measures on the same individual into account and allows for missing measurement data assuming that data are missing at random.
Exacerbations at 12 weeks which was intended as a covariate was a significant predictor of missing outcome measure at follow up (χ (1) = 4.16, p = 0.041) and was retained as a covariate.
For the longitudinal analyses, missing outcome measures will be treated as missing at random.
Instead, we assumed that any missing assessments of the clinical anchors and HRQOL health-utility measures were missing completely at random (MCAR), meaning that our results would be similar whether or not there were missing data.
For example, missing blood pressure measurements may be lower than measured blood pressures but only because younger people may be more likely to have missing blood pressure measurements Missing not at random Even after the observed data are taken into account, systematic differences remain between the missing values and the observed values.
