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Fig. 1 | BMC Medical Research Methodology

Fig. 1

From: A multiple imputation method based on weighted quantile regression models for longitudinal censored biomarker data with missing values at early visits

Fig. 1

Patients’ X-ray visits (organized at ≥ 2-year intervals) over time with indication of unobserved and observed CRP data. Patients in the cohort comprises three different groups of patients depending on the study that they were first enrolled in: Study I-A CRP data collection was not a part of the protocol (Patient A and B); Study I-B The original protocol had a screening visit where X-rays were collected but no blood samples (Patient C), but a protocol amendment led to a combining of the screening and baseline visit resulting in blood and X-rays collected at the first visit (Patient D); Study II both blood samples and X-rays were collected starting from their first visit (Patient E)

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