Finally, at the analysis stage, much care must be taken to assess data quality, develop appropriate metrics, deal with missing data, choose appropriate statistical methods and models for estimation and inference, assess the sensitivity of the results and inferences, and produce accurate estimates of population-level variables, based on the sample statistics.
Last Observation Carried Forward (LOCF) will be used for missing data when appropriate.
Second, if the missing data have a monotone pattern, then it is possible to impute the variables in increasing order of amount of missing data, using appropriate generalised linear models of each variable on the previous variables.
Group comparisons were made by means of Student t test for continuous variables, Chi2 test for categorical variables or ANOVA with Bonferroni correction for post-hoc tests with list wise exclusion of missing data as appropriate.
It is thus apparent that no method of dealing with missing data is appropriate under all conditions, and the best approach will depend on the degree of data missingness and the structure of the underlying missing data – correlations of missing covariate and outcome data.
In any case, reasons for missing data should inform appropriate selection of analysis methods and accurate data interpretation [16, 17].
Key topics in efficacy (N = 18) and safety (N = 13) requests were endpoints that were missing or not accepted by G-BA (n = 8 and n = 2, respectively), missing data against the appropriate comparator (n = 4 and n = 5, respectively) and missing long-term data (n = 4 and n = 2, respectively).
We will examine the structure and pattern of missing data and, if appropriate, will present a sensitivity analysis based on data imputed using a multiple imputation model.
Because of the nature of this analysis, the imputation of missing data was not appropriate; all analyses are based on patients with data available at the visit of interest ("as-observed").
If judged appropriate, missing data will be imputed, and resulting imputed datasets will be analysed and reported, together with appropriate sensitivity analyses.
