SFTPD and idiopathic interstitial pneumonia: However, no statistically significant differences in serum SP-D levels were observed between the death and survival groups for idiopathic pulmonary fibrosis (IPF) (WMD = 27.08 ng/mL, 95% CI: −14.49-68.65, p=0.202) and dermatomyositis-associated ILD (WMD = −18.28 ng/mL, 95% CI: −74.25-37.68, p=0.522) (Figure 8).