The fading of reported effectiveness. A meta-analysis of randomised controlled trials

Table 3 Bivariate qualitative analyses of all investigated parameters. Significant correlations (P < 0.05) are highlighted by bold digits

	Reported effect size*			Baseline			Study size			Treatment group^†
	Ph	R^‡	P-value	Ph	R	P-value	Ph	R	P-value	Ph	R	P-value
Year of Publication	P:	-0.5360	<.0001	P:	-0.6056	<.0001	P:	0.2444	0.0517	P:	-0.4092	0.0008
	A:	0.0305	0.8618	A:	-0.1518	0.3840	A:	0.1237	0.4789	A:	-0.3207	0.0603
	T:	-0.5043	<.0001	T:	-0.3955	0.0004	T:	0.4512	<.0001	T:	-0.4513	<.0001
	L:	-0.4642	0.0074	L:	-0.3413	0.0559	L:	-0.0346	0.8508	L:	-0.3167	0.0774
Reported effect size	1.00			P:	0.2591	0.0387	P:	-0.1899	0.1327	P:	0.1598	0.2073
				A:	-0.1454	0.4045	A:	0.0381	0.8281	A:	-0.4339	0.0092
				T:	0.6949	<.0001	T:	-0.1364	0.2432	T:	0.1565	0.1801
				L:	0.8745	<.0001	L:	0.2206	0.2251	L:	0.0289	0.8753
Baseline				1.00			P:	-0.2897	0.0202	P:	0.0872	0.4933
							A:	-0.0868	0.6201	A:	0.0848	0.6282
							T:	-0.1923	0.0983	T:	0.0686	0.5587
							L:	0.2673	0.1392	L:	-0.1069	0.5604
Study size							1.00			P:	0.0566	0.6568
										A:	0.1106	0.5269
										T:	-0.2723	0.0181
										L:	-0.3557	0.0457

Abbreviations: Ph, pharmaceutical; T, Timolol; L, Latanoprost; P, Pravastatin; A, Atorvastatin.
* Reported effect size for Pravastatin and Atorvastatin is measured in relative terms (%), for Timolol and Latanoprost in absolute terms (mmHg).
^† As the parameter treatment group only has the possibilities control group (= 0) or experimental group (= 1), point biserial correlation was used.
^‡ R: Pearson correlation coefficient.

ISSN: 1471-2288