Table 4

Potential prognostic factors for interstitial pneumonia with autoimmune features (IPAF)*

Potential prognostic factors†UnivariateMultivariate
StudyEffect size (HR (95% CI))StudyEffect size (HR (95% CI))
Age (/1 year)Oldham et al 201638 1.06 (1.03 to 1.08) Oldham et al 201638 1.05 (1.02 to 1.08)
Dai et al 201842 1.04 (1.01 to 1.07) Dai et al 201842 1.07 (1.02 to 1.12)
Ito et al 201744 1.07 (1.03 to 1.11) Ito et al 201744 1.04 (1.01 to 1.06)
Kim et al 201948 1.06 (1.03 to 1.09) Kim et al 201948 1.06 (1.03 to 1.10)
Men (vs women)Oldham et al 201638 1.54 (0.91 to 2.60)Oldham et al 201638 1.65 (0.92 to 2.97)
Dai et al 201842 1.89 (0.94 to 3.80)
Ito et al 201744 1.98 (0.92 to 4.25)
Kim et al 201948 1.50 (0.87 to 2.60)
Ever smoker (vs never smoker)Oldham et al 201638 0.92 (0.54 to 1.54)Oldham et al 201638 1.11 (0.60 to 2.05)
Ahmad et al 201740 7.18 (1.31 to 39.26) Dai et al 201842 2.11 (1.02 to 4.36)
Dai et al 201842 2.44 (1.19 to 5.00)
Ito et al 201744 1.27 (0.59 to 2.73)
Kim et al 201948 1.47 (0.84 to 2.55)
UIP (HRCT and/or SLB) (vs nonUIP)‡Oldham et al 201638 2.40 (1.21 to 4.76) Oldham et al 201638 1.72 (0.83 to 3.56)
Adegunsoye et al 201739 6.11 (1.43 to 26.08) Adegunsoye et al 201739 5.35 (11.21 to 23.67)
Ahmad et al 201740 p=0.23 (log-rank)§Kim et al 201948 3.85 (1.99 to 7.43)
Dai et al 201842 1.55 (0.47 to 5.11)
Kelly and Moua 201746 p = 0.04 (log-rank )
Kim et al 201948 4.47 (2.54 to 7.88)
Percentage of predicted FVC (/10%)Oldham et al 201638 0.90 (0.78 to 1.05)Oldham et al 201638 1.00 (0.78 to 1.29)
Ito et al 201744 0.82 (0.67 to 1.00)
Kim et al 201948 0.93 (0.80 to 1.09)
Percentage of predicted DLCO (/10%)Oldham et al 201638 0.74 (0.63 to 0.86) Kim et al 201948 0.66 (0.57 to 0.78)
Ito et al 201744 0.90 (0.70 to 1.16)
Kim et al 201948 0.75 (0.64 to 0.87)
  • *Italic bold indicates statistical significance.

  • †Potential prognostic factors were defined as any clinical information that was reported by at least three studies.

  • ‡UIP pattern was confirmed based on the finding of HRCT scan in three studies (Oldham et al,38 Ahmad et al, 40 Dai et al,42), pathological finding in one study (Adegunsoye et al 39) and either findings in two studies (Kelly and Moua,46 Kim et al,4848).

  • §Survival was estimated by the Kaplan-Meier survival curve and the log-rank test demonstrated that the prognosis of IPAF-UIP tended to be worse than that of IPAF-nonUIP.

  • ¶Survival was estimated by the Kaplan-Meier survival curve and the log-rank test demonstrated that the prognosis of IPAF-UIP was significantly worse than that of IPAF-nonUIP.

  • DLCO, diffusing capacity of the lung for carbon monoxide; FVC, forced vital capacity; HRCT, high-resolution computed tomography; SLB, surgical lung biopsy; UIP, usual interstitial pneumonia.