Fig. 1

Examples on response patterns and missing data indicator scores. Each line represents the response pattern of one subject, listed according to increasing scores on the Retention indicator. The scores are standardized between 0 and 100. A subject responding only at baseline will get a score of zero on all indicators (subject 1); while a subject responding to all follow-ups will get a score of 100 on all indicators (subject 23). The 23 response patterns illustrated in this figure are all drawn from observed response patterns among the 420 subjects of the Norwegian sample dataset, with the exception for subject 16 who is added for illustrative purposes. See main text for more detailed description of the three missing data indicators