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. 2020 Sep 14;20:297. doi: 10.1186/s12876-020-01417-6

Table 2.

Subgroup analysis of prevalence of GERD

Variable Studies (N) Sample (N) Heterogeneity 95% CI Pooled prevalence (%)
Total subjects Event I2 P-Value
Daily Areas Center 6 12,884 680 98.44 <  0.001 2.37–8.47 4.52
East 2 2066 254 98.54 <  0.001 3.21–29.70 10.58
North 2 51,448 5947 98.98 <  0.001 1.09–23.40 5.48
Test for subgroup differences: Q = 1.559, df(Q) = 2, P = 0.459
Population Blood donors 1 3517 165 4.05–5.45 4.70
General population 8 59,873 6653 98.18 <  0.001 4.51–9.45 6.56
Health care worker 1 3008 63 1.64–2.68 2.10
Test for subgroup differences: Q = 38.389, df(Q) = 2, P <  0.001
Year of studies 1991–2004 6 11,691 849 98.65 <  0.001 4.03–13.07 7.37
2005–2013 4 54,707 6032 99.01 <  0.001 1.20–10.51 3.64
Test for subgroup differences: Q = 1.256, df(Q) = 1, P = 0.263
Quality of studies Low risk 5 55,271 6282 98.52 <  0.001 4.21–12.39 7.31
Moderate risk 5 11,127 600 98.46 <  0.001 2.08–8.54 4.26
Test for subgroup differences: Q = 1.380, df(Q) = 1, P = 0.240
Method of data collection Questionnaire + Interview 7 61,932 6337 99.06 <  0.001 2.14–7.81 4.12
Interview 3 4466 545 98.91 <  0.001 6.53–18.38 11.14
Test for subgroup differences: Q = 5.488, df(Q) = 1, P = 0.019
Sex The odds ratio of females to males: 1.503 (95% CI: 1.153–1.59, P = 0.003); Heterogeneity: I2: 68.49%, P = 0.013
Weekly Areas Center 9 42,825 4880 99.34 <  0.001 7.92–15.92 11.31
East 2 2066 258 0 0.784 11.15–14.01 12.51
North 4 52,938 4317 91.08 <  0.001 7.04–11.38 8.98
South 4 12,559 2955 97.89 <  0.001 15.22–28.89 21.26
Test for subgroup differences: Q = 17.025, df(Q) = 3, P = 0.001
Population Blood donors 1 3517 197 4.89–6.41 5.60
General population 14 98,005 10,770 99.69 <  0.001 10.07–17.91 13.52
Health care worker 4 8866 1443 99.20 <  0.001 5.17–7.39 11.44
Test for subgroup differences: Q = 29.288, df(Q) = 2, P <  0.001
Year of studies 1991–2004 8 14,570 1453 97.25 <  0.001 7.86–13.56 10.37
2005–2013 11 95,818 10,957 99.70 <  0.001 9.95–20.04 14.27
Test for subgroup differences: Q = 1.947, df(Q) = 1, P = 0.163
Quality of studies Low risk 10 90,079 10,262 99.71 <  0.001 9.85–20.74 14.47
Moderate risk 9 20,309 2149 98.26 <  0.001 7.65–14.46 10.58
Test for subgroup differences: Q = 1.544, df(Q) = 1, P = 0.214
Method of data collection Interview 3 4466 568 0 0.892 11.77–13.73 12.72
Questionnaire 3 6170 1313 96.95 <  0.001 10.71–25.45 16.83
Questionnaire + Interview 13 99,752 10,529 99.61 <  0.001 8.38–15.92 11.63
Test for subgroup differences: Q = 1.815, df(Q) = 2, P = 0.404
Sex The odds ratio of females to males: 1.174 (95% CI: 0.974–1.414, P = 0.092); Heterogeneity: I2: 91.63%, P <  0.001
Monthly Areas Center 7 17,646 3591 97.55 <  0.001 15.36–22.91 18.84
East 1 1066 161 13.86–16.42 15.10
North 3 52,037 20,720 99.64 <  0.001 6.22–46.66 19.42
Test for subgroup differences: Q = 3.177, df(Q) = 2, P = 0.204
Population Blood donors 1 3517 795 98.91 <  0.001 21.25–24.01 22.60
General population 8 63,635 23,110 99.71 <  0.001 12.44–28.62 19.27
Health care worker 2 3597 567 98.23 <  0.001 11.92–18.40 14.87
Test for subgroup differences: Q = 14.531, df(Q) = 2, P = 0.001
Year of studies 1991–2004 6 15,453 3323 95.89 <  0.001 17.14–23.54 20.15
2005–2013 5 55,296 21,149 99.70 <  0.001 7.27–34.71 16.95
Test for subgroup differences: Q = 0.181, df(Q) = 1, P = 0.671
Quality of studies Low risk 5 55,271 21,159 99.70 <  0.001 7.82–35.92 17.90
Moderate risk 6 15,478 3313 96.03 <  0.001 16.42–22.85 19.43
Test for subgroup differences: Q = 0.042, df(Q) = 1, P = 0.838
Method of data collection Interview 3 8228 1891 97.45 <  0.001 15.89–26.03 20.50
Questionnaire + Interview 8 62,521 22,581 99.70 <  0.001 10.79–28.45 17.99
Test for subgroup differences: Q = 0.233, df(Q) = 1, P = 0.637
Sex The odds ratio of females to males: 1.126 (95% CI: 0.849–1.494, P = 0.411); Heterogeneity: I2: 96.68%, P <  0.001
Overall Areas Center 6 12,884 4823 97.38 <  0.001 32.01–42.62 37.16
East 1 1066 493 43.26–49.24 46.24
North 1 49,975 30,415 60.43–61.26 60.86
South 1 9264 5419 57.49–59.50 58.50
Test for subgroup differences: Q = 169.751, df(Q) = 3, P <  0.001
Population Blood donors 1 3517 1157 31.37–34.47 32.90
General population 7 66,664 38,913 99.43 <  0.001 38.49–53.12 45.71
Health care worker 1 3008 1080 99.09 <  0.001 34.20–37.63 35.90
Test for subgroup differences: Q = 16.155, df(Q) = 2, P <  0.001
Year of studies 1991–2004 5 10,691 4124 97.26 <  0.001 34.36–46.09 40.09
2005–2013 4 62,498 37,026 99.59 <  0.001 37.71–56.28 46.89
Test for subgroup differences: Q = 1.458, df(Q) = 1, P = 0.227
Quality of studies Low risk 5 63,062 37,471 99.15 <  0.001 43.12–56.23 49.67
Moderate risk 4 10,127 3679 98.20 <  0.001 28.59–42.77 35.36
Test for subgroup differences: Q = 8.008, df(Q) = 1, P = 0.005
Method of data collection Questionnaire + Interview 7 69,723 39,541 99.73 <  0.001 32.71–52.17 42.14
Interview 2 3466 1609 0 <  0.001 44.76–48.08 46.42
Test for subgroup differences: Q = 0.692, df(Q) = 1, P = 0.406
Sex The odds ratio of females to males: 1.111 (95% CI: 0.888–1.391, P = 0.358); Heterogeneity: I2: 97.96%, P <  0.001

CI Confidence intervals, N number