To our knowledge, this retrospective study is the first to estimate the current economic burden and analyze the health economic characteristics of HAIs in tertiary public hospitals of Central China. In this work, the estimated economic losses attributable to HAIs was $2047.07, accounting for 28.00% of per capita GDP ($7310.79) and 63.94% of per capita disposable income ($3201.68) in Henan Province, 2018 [8], which is both higher than that of a retrospective survey conducted by Jia HX et al. on 68 general hospitals in China, 2015 [12] and a research did in a referral hospital of Iran, 2017 [13], but lower than the direct economic loss of HAIs estimated by Li H et al. in 5 tertiary public hospitals of Hubei Province, 2016 [14] and that of a similar study made in tertiary hospitals of German, 2015 [15]. On the one hand, it is because the sample size and survey region vary among these studies. On the other hand, by assuming that the economic variables related to hospitalization obey the normal distribution, most of the existing studies used mean as the statistical indicator to describe the central tendency of their distributions [16, 17]. Nevertheless, the variables of hospitalization cost and economic loss in our study did not obey the normal distribution, which skewed to the right with a heavy tail, so the statistical indicator of median (lower and upper quartile) was adopted to estimate the economic loss.
In accordance with the results of current researches [17–19], the subgroup analysis shows that the economic losses caused by VAP and CAUTI were approximately 3 to 4 times higher than those caused by the other HAIs of their corresponding systems, while marginal difference was found when it comes to CLABSI, probably because of the limited sample size and low power of U test. We also found that the economic loss attributable to HAIs came mainly from pharmaceutical cost, of which additional antimicrobial drug cost accounted for about 60%. It could be explained by the fact, that antimicrobial drugs are needed to fight against infections, but along with physician's prescription comes the irrational use of antimicrobial drugs (i.e., using drug under no indication of infection, excessive dosage and overlong duration of treatment) [20], which is an independent risk factor for antimicrobial resistance [21, 22]. Meanwhile, the infection of Multiple Drug Resistant Organism (MDRO) not only causes huge economic losses, as our study and other relevant studies show [23, 24], but also increases the irrational and inappropriate use of antimicrobial drugs. Infection and antimicrobial resistance complement each other and come to a vicious circle. Therefore, the result of our study is precisely a reminder of the importance of monitoring drug prescription and controlling drug abuse for the reduction of medical burden and the prevention of MDRO infection.
In addition, this study provides the first estimate of the HAI burden on patients with different medical insurance types and payment systems, which indicated that, the HAIs occurred in patients who had CMI, UEBMI or URBMI caused huge waste of healthcare resources. It was not surprising, given that the HSIs-PS is still covering most cities of Henan Province. Under this system, the excess hospitalization cost caused by HAI are mostly payed for by the medical insurance institutions and a small remaining part by the patients themselves, while the hospitals do not bear the burden basically. As the result of this study showed, the economic losses attributable to HAIs in HSIs-PS were almost 5 times higher than those in DRGs-PPS, which quantifies payment criteria of different diagnosis related groups classified by the complexity of diseases and thus limits the waste of medical resources to some extent. Therefore, some developed countries strongly support the investment of HAI prevention by the medical insurance funds [25], and have established some lists of specific HAIs that are referred to as “no tolerance” events, thereby reducing the reimbursements to hospitals [26, 27].
Our study has several limitations. Considering that the economic burden of HAI includes direct loss of prolonged stay, anti-infection treatment and readmission, as well as the indirect loss which mainly consists of the reduced working hours of family members due to hospital care and the declined labor capacity of patients themselves due to infection and even disability, the total losses attributable to HAIs were underestimated in our research. Moreover, although we confirmed that there was a remarkable negative correlation between the incidence rate of HAI and the cost of its prevention, the cause-and-effect relationship between them cannot be proven by this retrospective case-control study. Further prospective studies are needed to address this issue and validate the importance of maintaining the ongoing financial investments in HAI prevention and control.