The effects of diagnosis-intervention packet (DIP) payment reform on inpatient healthcare in China - a systematic literature review

Abstract

Background: The diagnosis-intervention packet (DIP) is a health insurance payment method invented in China. It has been piloted in 71 cities. However, the evidence of its effects on inpatient healthcare in China remains fragmented. This study aims to systematically evaluate the effects of DIP payment on inpatient healthcare in China. Method: A systematic review was conducted. We searched literature databases of PubMed, Web of Science, Scopus, China National Knowledge Infrastructure (CNKI), and Wanfang database for primary studies examining the effects of DIP payment on healthcare efficiency, healthcare providers’ behaviour, and quality in China. We performed a narrative synthesis of outcomes regarding expenditure per case (EPC), length of stay (LOS), behaviour of upcoding and patient selection, in-hospital mortality, readmission rates, and assessed the quality of evidence. Results: 32 studies met the inclusion criteria, comprising 18 controlled before-andafter studies and 14 interrupted time series analyses, covering populations from specific groups to all inpatients. After DIP implementation, EPC and LOS initially rose strategically, then declined over time. DIP was also associated with a slight reduction in in-hospital mortality, though findings on readmission rates were inconsistent. Upcoding behaviour was consistently reported. However, the overall evidence quality was low to very low due to study design limitations and potential risk of bias. Conclusion: Short-term strategic responses to DIP reduced inpatient efficiency, but longer-term efficiency gains may enhance it. The policy has not been found to compromise quality and may even yield marginal improvements. However, DIP has also induced unintended upcoding behavior. Oversight mechanisms should accompany DIP rollout. Rigorous comparative studies, particularly RCTs, are warranted for long-term evidence.