Table 2 Pooled risk estimates of fecundability and female alcohol consumption in subgroup results.

From: Female alcohol consumption and fecundability: a systematic review and dose-response meta-analysis

Subgroup analysis

No. of studies

Summary RR (95%CI)

Heterogeneity

Publication bias

P value for Heterogeneity

P

I 2(%)

Begg’s test

Egger’s test

Overall

19

0.87 (0.78, 0.95)

0.001

89.6

0.069

0.169

 

Dose

  Non vs. lighter

15

0.89 (0.82, 0.97)

0.001

90.3

0.113

0.412

0549

  Non vs. moderate

14

0.77 (0.61, 0.94)

0.001

90.7

0.381

0.152

 

Study design

  Cohort

12

0.93 (0.86, 1.00)

0.001

77.3

0.732

0.761

0.157

  Case-control

7

0.77 (0.53, 1.01)

0.001

92.6

0.230

0.040

 

Geographical area

  Europe

11

0.93 (0.78–1.08)

0.001

90.2

0.755

0.644

0.322

  America

8

0.80 (0.67–0.93)

0.001

89.8

0.009

0.055

 

Type of population

  General

8

0.87 (0.76, 0.98)

0.001

93.1

0.108

0.222

0.854

  Hospital

5

1.00 (0.81, 1.20)

0.020

65.8

0.806

0.692

 

  Worker

3

0.65 (0.35, 0.94)

0.021

74.2

0.999

0.858

 

  Agricultural

2

0.78 (0.32, 1.25)

0.001

94.1

0.999

 

  Nurses

1

1.01 (0.85, 1.17)

 

Women’s mean Age

  <25

2

0.84 (0.69, 1.00)

0.273

16.9

0.999

0.540

  25–30

10

0.87 (0.72, 1.02)

0.001

91.9

0.474

0.315

 

  ≥30

5

0.84 (0.56, 1.12)

0.001

91.6

0.086

0.076

 

  NA

2

0.98 (0.95, 1.00)

0.970

0

0.999

 

Time_exposure

  Half-year

4

0.75 (0.42, 1.09)

0.001

95.9

0.308

0.185

0.501

  One-year

9

0.95 (0.88, 1.01)

0.002

67.5

0.917

0.796

 

  Two-years

6

0.84 (0.60, 1.09)

0.001

87.4

0.452

0.127

 

Definition of outcome

  Waiting Time to Pregnancy

12

0.85 (0.73, 0.96)

0.001

92.8

0.537

0.364

0.832

  Infertility Occurrence

5

0.91 (0.77, 1.06)

0.008

71.0

0.462

0.043

 

  Ovulatory Infertility

2

0.87 (0.60, 1.15)

0.022

80.9

0.999

 

Diagnostic method of outcome

  Self-reported

11

0.97 (0.91, 1.03)

0.001

67.5

0.876

0.792

0.043

  Clinically-confirmed

8

0.74 (0.55, 0.93)

0.001

88.6

0.035

0.046

 

Type alcoholic

  Wine

5

0.98 (0.85, 1.11)

0.001

91.4

0.327

0.264

 

  Beer

5

1.02 (0.99, 1.05)

0.137

42.7

0.327

0.303

0.242

  Spirits

5

0.92 (0.83, 1.01)

0.413

0

0.327

0.977

 

Method of alcohol consumption assessment

  SAQ

15

0.83 (0.73, 0.92)

0.001

91.5

0.166

0.945

0.008

  FFQ

4

1.03 (0.95, 1.10)

0.295

19.0

0.089

0.002

 

Quality score

  NOS = 8

14

0.91 (0.79–1.02)

0.001

88.8

0.324

0.284

0436

  NOS ≤ 7

5

0.76 (0.49–1.02)

0.001

92.6

0.086

0.250

 
  1. FFQ: Food-Frequency Questionnaire; NA: Not Available; NOS: Newcastle-Ottawa Scale; SAQ: Self-Administered Questionnaire; RR: Risk Ratio.