Correlation meta-analysis

Study	Size	Correlation	Approximate 95% CI		
1	1.484	0,038	-0,012911	0,088714	Kamariah, 2010	
2	200	-0,3	-0,421209	-0,168262	Firoozeh, 2011	
3	252	0,04	-0,083988	0,162768	Kourosh, 2011	
4	211	0,95	0,934892	0,961672	Ali, 2011	
5	33.982	0,21	0,199814	0,220141	Mahdi, 2011	
6	225	0,128	-0,002838	0,25453	Imani, 2016	
7	750	0,63	0,584786	0,671312	Onete, 2012	
8	270	0,651	0,57642	0,714824	Rwandema, 2017	
9	120	0,03	-0,150048	0,208122	Affum, 2014	
10	120	-0,159	-0,328869	0,020835	Palak, 2017	
11	193	0,215	0,07607	0,345741	Sikhwari, 2014	
12	480	0,189	0,101212	0,273868	Sita, 2014	
13	202	0,57	0,468842	0,6564	Taisha, 2010	
14	570	0,43	0,360609	0,494657	Michelle, 2009	

Stratum	Standardized effect	Variance	% Weights (fixed, random, size)		
1	0,038018	0,000675	3,795781	7,353243	3,79938	Kamariah, 2010	
2	-0,30952	0,005076	0,504908	7,069424	0,512046	Firoozeh, 2011	
3	0,040021	0,004016	0,638183	7,135767	0,645178	Kourosh, 2011	
4	1,831781	0,004808	0,533101	7,086108	0,540208	Ali, 2011	
5	0,213171	0,000029	87,08768	7,39682	87,001715	Mahdi, 2011	
6	0,128706	0,004505	0,568983	7,105045	0,576052	Imani, 2016	
7	0,741416	0,001339	1,91455	7,309006	1,920172	Onete, 2012	
8	0,777032	0,003745	0,684317	7,152912	0,691262	Rwandema, 2017	
9	0,030009	0,008547	0,299869	6,860582	0,307228	Affum, 2014	
10	-0,160361	0,008547	0,299869	6,860582	0,307228	Palak, 2017	
11	0,218408	0,005263	0,486967	7,057848	0,494124	Sikhwari, 2014	
12	0,1913	0,002096	1,222544	7,259128	1,22891	Sita, 2014	
13	0,647523	0,005025	0,510034	7,072588	0,517166	Taisha, 2010	
14	0,459897	0,001764	1,453213	7,280948	1,459331	Michelle, 2009	

Hedges-Olkin fixed effects
Pooled correlation = 0,224879 (95% CI = 0,215437 to 0,234278)
Z (test correlation differs from 0) = 45,191989  P < 0,0001

Non-combinability of studies
Cochran Q = 1.029,604289  (df = 13)  P < 0,0001
Moment-based estimate of between studies variance = 0,108944
I² (inconsistency) = 98,7% (95% CI = 98,6% to 98,9%) 

Hedges-Olkin random effects
Pooled correlation = 0,334508 (95% CI = 0,170255 to 0,480675)
Z (test correlation differs from 0) = 3,874953  P = 0,0001

Bias indicators
Begg-Mazumdar: Kendall's tau = 0,142857  P = 0,7195 (low power)
Egger: bias = 9,311441 (95% CI = 0,394606 to 18,228275)  P = 0,0432

Schmidt-Hunter
Weighted mean correlation (95% CI): 0,217547 (0,159657 to 0,275438)
Z (test correlation differs from 0) = 7,365345 P < 0,0001

Observed variance across studies: 0,012214
Variance due to sampling error: 0,000325
Variance in the population correlations: 0,011888
95% Credibility interval for weighted mean correlation: 0,003845 to 0,43125

Indicators of homogeneity/heterogeneity:
1.	Residual standard deviation (should be smaller than 1/4 WMC: 0,054387): 0,109034	
2.	Percent of observed variance accounted for by sampling error (should be at least 75%): 2,664406	
3.	Chi-square test of heterogeneity: 525,44538 P < 0,0001