NPPB and infection: Predictive variables identified in these models include lumbar disc displacement [22], age [22, 25, 28], hearing loss [22], infections [22], vascular diseases [22], physiological scores [26, 28], urinary output [28], treatment with statins [29], and laboratory tests including albumin [25] (26), lactate [25, 28], blood urea nitrogen, BNP and blood neutrophile-to-lymphocyte ratio [27], as well as NT-proBNP [29].