This study was a retrospective longitudinal study targeting to measure the burden of PVP/PKP due to OVCF in China. To our knowledge, our study was the first to estimate utilization of PVP/PKP procedures and their costs for OVCF treatment in China by analyzing real-world city-wide claims data. We noted the utilization of PVP/PKP was high for OVCF patients with 28.66% PVP/PKP surgery rate and 7.95% 2-year cumulative re-surgery rate. Median LOS in hospital was 9 days, and median time interval of re-surgery was 139 days. Hospitalization costs due to PVP/PKP were high: per hospitalization cost averaged 35,906 CNY, and annual hospitalization expenses in the metropolitan city totaled 187 million CNY. It brought significant burden to both medical insurance institution and patients.
Overall, the results of this study were comparable with those of previous studies. In this study, the number of female OVCF patients was about 2.3 times that of male patients; this is consistent with the higher risk of OVCF in females in other studies (1,4,7,17). The surgery rate of PVP/PKP in OVCF patients in our study was also similar to the finding of another study at 23.1% (18). The comparison of re-surgery rate among studies was not conducted due to the lack of studies on PVP/PKP re-surgery rate.
Whether it is PVP or PKP, surgery related inpatient costs are high. In contrast, taking a short-term view, PVP seems to be better than PKP because there was no significant difference in the re-surgery rate between PVP and PKP, but the cost of PKP was nearly 30% higher than that of PVP. Another clinical study in China also recommended PVP because the clinical result (pain relief) has little difference but the cost of PKP is higher (19). The costs associated with vertebral fractures in many countries are well documented. In America, the cost per surgery related hospitalization was 7,805 USD (PVP) and 12,032 USD (PKP) in 2006, 9,837 USD (PVP) and 13,187 USD (PKP) in 2007 and 2008 (20,21). The results of US studies are similar to our study, where the cost of PKP hospitalization is higher than PVP. However, it is worth noting that in terms of long-term costs, the results are reversed. In America, the two-year cumulative costs were 44,496 USD for PVP and 41,339 USD for PKP between 2006 and 2010 (22). In Germany, patients’ four-year cumulative costs were 42,510 EUR for PVP and 39,014 EUR for PKP between 2006 and 2010 (23). One reason is that patients with PKP surgery have less drugs use and lower maintenance costs after surgery. PKP significantly reduced 6.8%–7.9% treatment costs during the 2-year post-surgery periods in America and reduced 33% painkiller costs during the 4-year post-surgery periods in German (22,23).
Aside from surgery intervention, conservative treatment for OVCF is widely employed in China. Conservative treatment is recommended for mild/chronic OVCF, while severe/acute OVCF are treated with surgery (24). Anticoagulant therapy of low molecular weight heparin calcium injection can be given during bed rest; non-steroidal anti-inflammatory analgesics are mainly used to relieve acute pain; anti-osteoporosis medication, such as alendronate sodium, and complex calcium carbonate vitamin D tablets can also be employed (25,26). In terms of treatment effect, for pain relief, the short-term effect of surgery is better than that of conservative treatment, and no difference was observed in terms of long-term effect (27–30). However, from the perspective of recovery of vertebral stability and vertebral height, surgery is superior to conservative treatment (29).
Although successful PVP/PKP treatment for OVCF can effectively alleviate pains and other symptoms, the procedures are not free of untoward effects. Studies have explored that the PVP/PKP may accelerate local bone absorption due to bone cement, thereby increasing the risk of recurrent fracture of the surgical vertebra (31–34). In addition, studies also reported that additional stress of adjacent vertebrae caused by the cement augmentation and cement leakage are important factors in causing new adjacent vertebral fractures after PVP/PKP (35–38).
To avoid OVCF, anti-osteoporosis therapy should be considered for the primary prevention. Osteoporosis and resulting osteoporotic vertebral fractures typically develop silently with a long time window from the initial decrease in bone density to the occurrence of OVCF. Use of anti-osteoporosis drugs can reduce the risk of fractures. For women with osteoporosis but without vertebral fractures, alendronate significantly reduced the first vertebral fracture by 44% (39). Studies have shown that anti-osteoporosis treatment after fracture can reduce the risk of re-fracture by 40% within three years (40). In this regard, anti-osteoporosis treatment should be considered as part of long-term treatment strategies to reduce the risk of fracture (41–44). Although anti-osteoporosis therapy plays a significant role in OVCF prevention, the current situation of drug use is not optimistic. A study in mainland China showed only 13.9% patients used anti-osteoporosis drugs before fractures (18). Compounding the problem is poor compliance with the medications as short-term medication intake has no evidentiary clinical benefits for fracture prevention (45–47). In China, an analysis of medical insurance claims database from 2009 to 2010 showed that the adherence to bisphosphonate treatment was even worse with the mean Medication Possession Ratio (MPR) being 0.34, 0.22, and 0.15 at the 3rd, 6th, and 12th month over the follow-up period, respectively. And only 2.1% patients were observed with high adherence (MPR>0.8) during the 12-month follow-up (48).
The strength of our study stems from a well-defined study population which was population-based, i.e. residents of the metropolitan city covered by government health insurance were all included. The findings are likely to be more robust than those derived from a single hospital or hospitals from convenient sampling. Nevertheless, our study also has a number of limitations. We assumed all vertebral fracture cases meeting eligibility criteria were osteoporotic. This may include a few patients with non-osteoporotic vertebral fractures. There may be omissions in selecting PVP/PKP patients due to lack of standardized procedure name. All these will lead to the deviation between the calculated and the actual surgery rate. Second, re-surgery rate calculation could be inaccurate due to the lack of the knowledge on patients’ history. Finally, it should be cautioned about extrapolation of findings to other regions or cities in China or to patients without health insurance because of variation in adopting surgical intervention for OVCF, health insurance coverage schemes and steep cost for self-pay patients.