Purpose We evaluated the cardiovascular risk associated with dipeptidyl peptidase‐4 inhibitors (DPP‐4Is) as monotherapy compared with other antidiabetic drugs in Japan. Methods We conducted a nationwide cohort study involving 2 716 000 diabetes patients in Japan. New users of any antidiabetic drug as monotherapy between 1 April 2010 and 31 October 2014 were identified. Occurrences of myocardial infarction (MI), heart failure (HF), and stroke requiring hospitalization associated with DPP‐4Is were compared with those associated with biguanides (BGs), sulfonylureas (SUs), or α‐glucosidase inhibitors (α‐GIs). Adjusted hazard ratios (aHRs) for these outcomes were estimated by Cox proportional hazards model. Propensity score standardization was used to control for confounding. Results We identified 1 105 103 patients using DPP‐4Is, 278 280 patients using BGs, 273 449 patients using SUs, and 217 026 patients using α‐GIs. The risks of MI and HF for DPP‐4I users were significantly higher than those for BG users (MI: aHR, 1.48 [95%CI, 1.20‐1.82], HF: aHR, 1.46 [95%CI, 1.31‐1.62]), while significantly lower than those for SU users (MI: aHR, 0.84 [95%CI, 0.72‐0.98], HF: aHR, 0.86 [95%CI, 0.81‐0.92]). The risk of MI for DPP‐4I users was similar to that for α‐GI users, while the risk of HF for DPP‐4I users was slightly higher than for α‐GI users (MI: aHR, 0.98 [95%CI, 0.82‐1.17], HF: aHR, 1.12[95%CI, 1.04‐1.21]). Conclusions Risk of MI and HF requiring hospitalization associated with DPP‐4Is as monotherapy was significantly higher than BGs, significantly lower than SUs, and similar to α‐GIs.

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.

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.