| No. of reports | Prevalence rate (%) | Lower Limit (LL) | Upper Limit (UL) | I2 (%) | P for heterogeneity | P value* between groups |
---|---|---|---|---|---|---|---|
Primary analysis | 25 | 0.47 | 0.39 | 0.55 | 99.50 | <  0.001 |  |
Subgroups analyses | |||||||
 Study period | |||||||
  2010–2019 | 17 | 0.48 | 0.38 | 0.58 | 99.60 | <  0.001 | 0.51 |
  2000–2009 | 6 | 0.45 | 0.36 | 0.55 | 91.10 | <  0.001 | |
  1988–2000 | 2 | 0.37 | 0.26 | 0.49 | 63.80 | 0.0970 | |
 Study location | |||||||
  Asia | 9 | 0.46 | 0.29 | 0.62 | 99.50 | <  0.001 | 0.664 |
  Australia/New Zealand | 8 | 0.43 | 0.33 | 0.52 | 95.50 | <  0.001 | |
  Europe | 8 | 0.51 | 0.38 | 0.65 | 99.60 | <  0.001 | |
 Practice settings | |||||||
  Urban community health center | 7 | 0.41 | 0.22 | 0.60 | 99.50 | <  0.001 | 0.95 |
  Rural community health center | 8 | 0.48 | 0.34 | 0.49 | 97.20 | <  0.001 | |
  Primary care setting | 10 | 0.47 | 0.39 | 0.55 | 99.60 | <  0.001 | |
 Survey method | |||||||
  Questionnaire | 20 | 0.42 | 0.34 | 0.51 | 99.50 | <  0.001 | 0.008 |
  Questionnaire and interview | 5 | 0.69 | 0.52 | 0.86 | 94.30 | <  0.001 |