LAUSR

To the Editor: We read with great interest the article byWang et al. [1] about the relationship between platelet-to-lymphocyte ratio (PLR) and survival outcome of elderly patients with hip fracture. The authors performed a retrospective study of 460 cases to investigate the prognostic utility of PLR on one year all-cause mortality rate. They found that high PLR group had a high one year all-cause mortality rate, reaching the conclusion that high PLR was an independent predictor for one year all-cause mortality. Nevertheless, we have several queries related to this article. We found that the two groups of this study are not matched at baseline with respect to some parameters. Firstly, patients of the high PLR group are relatively older than the low PLR group reaching statistical significance (81.99 vs 78.02, p<0.001). Secondly, more intertrochanteric fracture patients existed in the high PLR group than in the low PLR group which is also significantly different (55.03% vs 44.05%, p=0.027). It is reported in the literature that patients with hip fracture of older age have worse outcomes and less survival years than younger ones [2]. It is also commonly recognized that patients with intertrochanteric fracture more often than not are in poorer health condition than those with femoral neck fracture and have higher mortality rates within one year after fracturing [3]. Age and the type of fracture both have impact on patients’ one year mortality rate, which may bring great bias to this study. We highly recommend the author to match the two groups with regard to some patient characteristics and parameters that are closely related to patients’ outcomes before conducting this comparison, which may make the result of this study more authentic and reliable. Although the author collected data regarding treatment details, they did not report what kind of surgery the patients underwent . Did they undergo inte rnal f ixa t ion , hemiarthroplasty, or total hip arthroplasty (THA)? Was there any difference between the two groups with regard to the type of surgery? To our knowledge, different types of surgery could lead to different patient outcomes and mortality rate. In a recent study from Danish National Registries on femoral neck fracture including 29,597 patients, patients treated for a displaced femoral neck fracture with arthroplasty had a higher risk of 30-day mortality compared with patients who had an undisplaced femoral neck fracture treated with internal fixation [4]. Furthermore, the author did not make it clear on the timing of patients undergoing surgery. As it was reported in a study of 73,557 hip fracture patients published on the Bone & Joint Journal, total delay of surgery over 48 hours would increase three day mortality [5]. Therefore, we would like to know if there was any difference between the two groups with regard to the timing of operation, since it may be the real reason leading to the difference in mortality rate other than PLR level.