Characteristics of hospital differences in missing of clinical laboratory test results in a multi-hospital observational database contributing to MID-NET® in Japan

Abstract

Background In Japan, a multiple-hospital observational database system, the Medical Information Database Network (MID-NET®), was launched for post-marketing drug safety assessments. These assessments will be based on datasets with missing laboratory results. The characteristics of missing data considering hospital differences have not been evaluated. We assessed the missing proportion and the association between missingness and a factor through case studies using a database system, a part of MID-NET®. Methods Seven scenarios using laboratory results before the prescription of the assessed drug as baseline covariates and data from 10 hospitals of Tokushukai Medical Group were used. The missing proportion and the association between missingness and patient background were investigated per hospital. The associations were assessed using the log of adjusted odds ratio (log-aOR). Additionally, an ad hoc survey was conducted to explore other factors affecting the missingness. Results For some laboratory tests, missing proportions varied among hospitals, such as 7.4–44.4% of alkaline phosphatase (ALP) and 8.1–31.2% of triglyceride (TG) among statin users. The association between missingness and affecting factors also differed among hospitals for some factors; example, the log-aOR of hospitalization associated with missingness of TG was − 0.41 (95% CI, − 1.06 to 0.24) in hospital 3 and 1.84 (95% CI, 1.34 to 2.34) in hospital 4. In the ad hoc survey focusing on ALP, hospital-dependent differences in the ordering system settings were observed. Conclusions Hospital differences in missing data appeared in some laboratory tests in our multi-hospital observational database, which could be attributed to the affecting factors, including the patient background.

Dealing with missing data in laboratory test results used as a baseline covariate: results of multi-hospital cohort studies utilizing a database system contributing to MID-NET® in Japan

“…As per a previous study, missing data were defined as “data that would be meaningful for the analysis but not available during a specific period before the first prescription date” [ 9 ]. The specific period, based on the results of this prior study, was set to 90 days.…”

“…Based on our previous research [ 9 ], we selected the scenarios of two cohort studies that evaluated the relation between drugs and their known risks (see Supplementary Fig. S 2 ).…”

“…Raebel et al, in their study using the US Food and Drug Administration Mini-Sentinel Distributed Database [ 6 ], reported that missing data sources of laboratory test results include testing outside of contracted laboratories, patient location where testing was conducted, patient clinical features, etc. In the study of the 10 MID-NET ® -collaborative hospitals of the Tokushukai Medical Group [ 9 ], authors reported that patient background and setting of ordering system of laboratory tests were the main missing data sources. Although their impact was not evaluated because they were unobserved, the measurement policies by physicians and institutions were considered as potential sources as well.…”

“…In the utilization of laboratory test results contained in MID-NET ® to confounding adjustments, it is not clear what impact different missing data methods have on the result. Furthermore, owing to the differences between hospitals in terms of the proportion of patients with missing data (hereinafter, “missing proportion”) and the relationship between missing data and patient background [ 9 ], hospital variations regarding missing data should be well-considered.…”

Regulatory Approval With Real-World Data From Regulatory Science Perspective in Japan

“…It stated that RWD can now be used for post-marketing surveillance by the Revised GPSP (7). Currently, Medical Information Database Network (MID-NET) is available to conduct such research (8,9).…”