Background
Methods
Eligibility criteria
Search strategy
Study selection and data collection process
Risk of bias in individual studies
Statistical analysis
Summary statistics
Data synthesis
Heterogeneity between studies
Meta-biases
Confirmation of risk and prognostic factors
Confidence in cumulative evidence
Results
Selection of studies
Demographic features of eligible studies
Study | Country | Study design | Subjects (n) (M/F) | Diagnosis of systemic autoimmune disease (n) | Age (years) (at the onset of AE) | Smoking (n (%)) | UIP pattern (n (%))a | Follow-up lengths (months) | Frequency of AE (n (%))/Incidence | All-cause mortality (n (%)) |
---|---|---|---|---|---|---|---|---|---|---|
Isobe [41] | Japan | Case–control | 2 (2/0) | RA2 | 74.0 ± 7.1 | – | 2 (100.0) | – | 2/8 (25.0) among RA-ILD | 2/2 (100.0) (overall) |
Lim [42] | Korea | Retrospective-cohort | 25 | Not specified | – | – | – | – | 25/76 (32.9) | – |
Park [43] | Korea | Retrospective-cohort | 4 (3/1) | RA3, SSc1 | median 58 (range 47–68) | 2 (50.0) | 3 (75.0) | – | 4/93 (4.3) among systemic autoimmune disease-ILDg | 4/4 (100.0) (overall) |
Song [44] | Korea | Retrospective-cohort | 14 (8/6) | RA14 | 68.1 ± 7.8d | 7 (50.0) | 14 (100.0) | – | 14/84 (16.7) among RA-ILD | 13/14 (92.9) (overall) |
Suzuki [45] | Japan | Retrospective-cohort | 27 | RA7, SSc11, PM/DM4, SS2, SLE2, MCTD1 | – | – | – | – | 27/205 (13.2) among systemic autoimmune disease-ILDc/3.19 per 100 patient-years, | – |
Tachikawa [46] | Japan | Retrospective-cohort | 15 (7/8) | RA6, SSc3, DM3, CADM3 | 63.3 ± 6.8 | 8 (57.1) (n = 14) | 4 (26.7) | – | – | (33.0) (90 days) |
Tomiyama [47] | Japan | Retrospective-cohort | 13 (3/10) | SSc13 | 49.3 ± 12.7 (at the onset of SSc) | – | – | – | 13/55 (23.6) among SSc-ILD | 6/13 (46.2) (overall) |
Akiyama [48] | Japan | Retrospective-cohort | 6 (2/4) | RA6 | 66.8 ± 6.2 (at the start of treatment) | 2 (40.0) (n = 5) | 3 (50.0) | – | 6/78 (7.7) among RA-ILD | – |
Cao [49] | China | Retrospective-cohort | 70 (35/35) | RA16, PM/DM8, SS25, MCTD6, ANCA-vasculitis5, IPAF10 | 65.8 ± 9.3d | 18 (25.7) | 70 (100.0) | – | 70/1168 (6.0) among systemic autoimmune disease-ILDg | – |
Enomoto [50] | Japan | Retrospective-cohort | 15 (11/4) | RA9, SSc2, MPA3, MPA + SS1 | median 71 (range 57–85) | 13 (86.7) | – | Median 56 (range 0–228)e | – | 5/15 (33.3) (1 month) |
7/15 (46.7) (3 months) | ||||||||||
11/15 (73.3) (overall) | ||||||||||
Hozumi [51] | Japan | Retrospective-cohort | 11 (6/5) | RA11 | median 72 (range 60–86) | 9 (81.8) | 6 (54.5) | Median 8.5 (range 1–17) (years)f | 11/51 (21.6) among RA-ILD | 7/11 (63.6) (overall) |
Ichiyasu [52] | Japan | Retrospective-cohort | 38 | RA6, SSc1, PM5, DM17, SS1, SLE1, MCTD1, MPA6 | – | – | – | – | – | (58.3) (90 days) |
Ishikawa [53] | Japan | Case–control | 9 (3/6) | Not specified | 56.4 ± 15.6 | – | – | – | – | 4/9 (44.4) (3 months) |
Liang [54] | China | Case–control | 64 (25/39) | PM15, DM36, CADM13 | 57.7 ± 11.9d | 14 (21.9) | 15 (23.4) | – | 64/483 (13.3) among IIM-ILD | 25/64 (39.1) (in-hospital or within 2 weeks after discharge) |
Manfredi [55] | Italy | Prospective-cohort | 9 (3/6) | RA1, SSc1, SS1, MCTD1, SSc + DM1, RA + SS1, ANCA-vasculitis1, IPAF2 | 67.8 ± 8.5 (at the diagnosis of ILD) | 1 (11.1) | 6 (66.7) | 23.9 ± 10.9f | 9/78 (11.5) among systemic autoimmune disease-ILDg/5.77 per 100 patient-years | 5/9 (55.6) (overall) |
Okamoto [56] | Japan | Retrospective-cohort | 4 | SSc4 | – | 4 (100.0) | – | 4/33 (12.1) among SSc-ILD | 4/4 (100.0) (overall) | |
Ota [57] | Japan | Retrospective-cohort | 12 (4/8) | RA12 | median 74.5 (range 50–80) | 4 (33.3) | 10 (83.3) | Median 19.5 (range 9–88)e | – | 2/12 (16.7) (overall) |
Parambil [58] | USA | Case–control | 6 (2/4) | RA4, PM2 | medina 68 (range 43–76) | 3 (50.0) | 2 (33.3) | – | – | 5/6 (83.3) (in-hospital) |
Silva [59] | Canada | Case–control | 8 (2/6) | RA3, PM/DM4, SS1 | median 62 (range 53–72) | – | 5 (62.5) | – | – | 6/8 (75.0) (overall) |
Singh [60] | India | Prospective-cohort | 15 (5/10) | RA1, SSc5, DM3, SS3, MCTD3 | 45.8 ± 13.9 | 4 (26.7) | 2 (13.3) | 24 ± 18.1f | 15/105 (14.3) among systemic autoimmune disease-ILDb | 5/15 (33.3) (in-hospital) |
Su [61] | China | Retrospective-cohort | 26 | Not specified | – | – | – | – | 26/161 (16.1) among systemic autoimmune disease-ILDg | 16/26 (61.5) (1 year) |
Suda [62] | Japan | Retrospective-cohort | 6 (4/2) | RA5, SS1 | 65.7 ± 5.3 | 5 (83.3) | 3 (50.0) | Mean 6.0 (years)f | 6/83 (7.2) among systemic autoimmune disease-ILDg | 5/6 (83.3) (overall) |
Toyoda [63] | Japan | Retrospective-cohort | 10 (7/3) | RA6, PM/DM2, SLE1, SS1 | median 73 (range 61–83) | 6 (60.0) | 8 (80.0) | – | 10/155 (6.5) among systemic autoimmune disease-ILDg | 1/10 (10.0) (30 days) |
3/10 (30.0) (90 days) | ||||||||||
7/10 (70.0) (overall) | ||||||||||
Yamakawa[64] | Japan | Retrospective-cohort | 11 | RA11 | – | – | 3 (27.3) | – | 11/96 (11.5) among RA-ILD | – |
Risk of bias in individual studies
Study | Study participation | Study attrition | Risk factor measurementa | Outcome measurement | Study confounding | Statistical analysis and reporting |
---|---|---|---|---|---|---|
Akiyama [48] | Low risk | High risk | Moderate risk | Low risk | High risk | High risk |
Cao [49] | Low risk | High risk | Moderate risk | Low risk | Moderate risk | Moderate risk |
Hozumi [51] | Low risk | High risk | Moderate risk | Low risk | Moderate risk | Moderate risk |
Ishikawa [53] | Moderate risk | Low risk | Low risk | Low risk | High risk | High risk |
Liang [54] | Low risk | Low risk | High risk | Low risk | High risk | Low risk |
Manfredi [55] | Low risk | High risk | Moderate risk | Low risk | High risk | High risk |
Okamoto [56] | High risk | Low risk | High risk | Low risk | High risk | High risk |
Silva [59] | Moderate risk | Low risk | Low risk | Low risk | High risk | High risk |
Singh [60] | Low risk | Low risk | Low risk | Low risk | Moderate risk | High risk |
Su [61] | Moderate risk | Low risk | Low risk | Low risk | High risk | High risk |
Suda [62] | Low risk | High risk | Moderate risk | Low risk | High risk | High risk |
Yamakawa [64] | Moderate risk | High risk | Low risk | Low risk | Moderate risk | High risk |
Study | Study participation | Study attrition | Prognostic factor measurementa | Outcome measurement | Study confounding | Statistical analysis and reporting |
Cao [49] | Low risk | High risk | Moderate risk | Low risk | Moderate risk | Moderate risk |
Enomoto [50] | Moderate risk | High risk | Moderate risk | Low risk | High risk | Moderate risk |
Ichiyasu [52] | High risk | High risk | Low risk | Low risk | High risk | High risk |
Liang [54] | Low risk | Low risk | Moderate risk | Low risk | Moderate risk | Low risk |
Manfredi [55] | Low risk | High risk | Moderate risk | Low risk | High risk | High risk |
Ota [57] | Low risk | Low risk | Moderate risk | Low risk | Moderate risk | High risk |
Parambil [58] | Low risk | Low risk | High risk | Low risk | High risk | High risk |
Silva [59] | Moderate risk | Low risk | Low risk | Low risk | High risk | High risk |
Singh [60] | Low risk | Low risk | Low risk | Low risk | Moderate risk | High risk |
Toyoda [63] | Low risk | High risk | High risk | Low risk | High risk | High risk |
Risk factors of AE of systemic autoimmune disease-ILD
Potential risk factorsa | Studiesb | Effect estimates (95% confidence interval)c |
---|---|---|
Demographic features | ||
Age | Hozumi [51] | HR 1.11 (1.01–1.20) (year) (at ILD diagnosis) |
Suda [62] | HR 1.19 (1.04–1.36) (year) (at initial presentation) | |
Cao [49] | HR 1.01 (0.97–1.04) (year)d | |
Akiyama [48] | MD − 2.60 (− 9.17 to 3.97) (year) (at the start of ILD treatment) | |
Manfredi [55] | MD 5.00 (− 3.06 to 13.1) (year) (at ILD diagnosis) | |
Liang [54] | MD 0.40 (− 3.48 to 4.28) (year)d | |
Sex (men) | Akiyama [48] | RR 1.36 (0.27–6.94) |
Manfredi [55] | RR 0.94 (0.25–3.50) | |
Cao [49] | HR 0.75 (0.43–1.30)e | |
Hozumi [51] | HR 0.90 (0.49–1.69) | |
Suda [62] | HR 1.31 (0.53–3.25) | |
Liang [54] | OR 1.00 (0.54–1.85) | |
Smoking history (ever-smoking vs. non-smoking) | Meta-analysis (n = 3) | HR 1.22 (0.57–2.60) |
Akiyama [48] | RR 1.19 (0.21–6.60) | |
Manfredi [55] | RR 0.16 (0.02–1.23) | |
Liang [54] | OR 1.10 (0.53–2.28) | |
Pulmonary function (before acute exacerbation) | ||
FVC | Cao [49] | HR 0.86 (0.56–1.31) (L) |
Hozumi [51] | HR 1.02 (0.99–1.06) (% of predicted value) | |
Manfredi [55] | MD − 7.60 (− 23.0 to 7.81) (% of predicted value) | |
DLCO | Cao [49] | HR 1.00 (0.97–1.03) (% of predicted value) |
Suda [62] | HR 1.05 (0.98–1.21) (% of predicted value) | |
Liang [54] | MD − 8.70 (− 14.4 to 3.01) (% of predicted value) | |
Manfredi [55] | MD − 12.3 (− 24.3 to 0.32) (% of predicted value) | |
Underlying radiological features | ||
UIP pattern on HRCT | Meta-analysis (n = 4) | RR 1.55 (0.57–4.25) |
Hozumi [51] | HR 1.95 (1.07–3.63) | |
Liang [54] | OR 1.40 (0.67–2.91) | |
Pre-treatment | ||
Corticosteroid | Cao [49] | HR 0.42 (0.22–0.80) |
Hozumi [51] | HR 0.97 (0.53–1.92) | |
Akiyama [48] | RR 3.48 (0.43–28.4) | |
Manfredi [55] | RR 2.41 (0.15–38.0) | |
Liang [54] | OR 1.04 (0.54–2.01) | |
Immunosuppressive agents | Cao [49] | HR 0.73 (0.42–1.25) |
Hozumi [51] | HR 0.76 (0.35–1.41) | |
Akiyama [48] | RR 0.45 (0.06–3.65) | |
Manfredi [55] | RR 7.21 (0.44–118.6) |
Potential risk factorsa | Study | Effect estimates (95% confidence interval) |
---|---|---|
Age | Suda [62] | HR 1.22 (1.05–1.50) (year) (at initial presentation) |
DLCO (before acute exacerbation) | Manfredi [55] | HR 0.95 (0.90–1.00) (% of predicted value) |
Liang [54] | OR 0.97 (0.95–0.99) (% of predicted value) | |
Potential prognostic factorsa | Study | Effect estimates (95% confidence interval) |
PaO2/FiO2 (at acute exacerbation) | Cao [49] | HR 0.99 (0.98–0.99) |
Prognostic factors of AE of systemic autoimmune disease-ILD
Potential prognostic factorsa | Studies (n)b | Effect estimates (95% confidence interval)c |
---|---|---|
Demographic features | ||
Age (at acute exacerbation) | Meta-analysis (n = 3) | MD 0.41 (− 8.74 to 9.57) (year) |
Manfredi [55] | MD 6.55 (− 4.40 to 17.5) (year)d | |
Liang [54] | MD 0.00 (− 6.49 to 6.49) (year) e | |
Enomoto [50] | HR 1.03 (p = 0.50) (year) | |
Sex (men) | Enomoto [50] | HR 3.19 (p = 0.29) |
Ishikawa [53] | OR 0.50 (0.03–8.95) | |
Liang [54] | OR 1.85 (0.66–5.17) | |
Singh [60] | RR 1.33 (0.32–5.58) | |
Smoking history (ever-smoking vs. non-smoking) | Singh [60] | RR 1.83 (0.46–7.25) |
Liang [54] | OR 1.22 (0.37–4.07) | |
Parambil [58] | OR 4.20 (0.12–152.0) | |
Pulmonary function (before acute exacerbation) | ||
FVC | Meta-analysis (n = 3) | MD − 5.95 (− 13.9 to 1.99) (% of predicted value) |
Enomoto [50] | HR 1.07 (p = 0.35) (%of predicted value) | |
Underlying radiological features | ||
UIP pattern on HRCT | Meta-analysis (n = 3) | OR 0.70 (0.24–2.08) |
Manfredi [55] | RR 2.00 (0.37–10.9) | |
Singh [60] | RR 0.42 (0.03–5.78) | |
Laboratory findings (at acute exacerbation) | ||
PaO2/FiO2 | Cao [49] | HR 0.989 (0.985–0.994) |
Enomoto [50] | HR 0.99 (p = 0.18) | |
Manfredi [55] | MD − 18.3 (− 77.4 to 40.9) | |
LDH | Cao [49] | HR 1.004 (1.002–1.005) (U/L) |
Enomoto [50] | HR 1.001 (p = 0.63) (IU/L) | |
Liang [54] | MD 24.2 (− 86.2 to 134.5) (U/L) |
Additional analysis
Quality of evidence
GRADE factors | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|
Risk factorsa | Analysisb | Phase | Study limitations | Inconsistencyc | Indirectness | Publication bias | Imprecision | Moderate/large effect size | Dose response gradient | Overall quality |
Outcome: all-cause mortality | ||||||||||
Age | Uni | 1 | + | − | − | + | − | − | − | Low |
Multi | 1 | + | N/A | − | + | − | − | − | Very low | |
DLCO | Uni | 1 | + | + | − | + | − | + | − | Very Low |
Multi | 1 | + | − | − | + | − | − | − | Very low |
GRADE factors | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|
Prognostic factorsa | Analysisb | Phase | Study limitations | Inconsistencyc | Indirectness | Publication bias | Imprecision | Moderate/large effect size | Dose response gradient | Overall quality |
Outcome: all-cause mortality | ||||||||||
PaO2/FiO2 | Uni | 1 | + | − | − | + | − | − | − | Very low |
Multi | 1 | + | N/A | − | + | − | − | − | Very low |