Table 1

Characteristics of studies included in the meta-analysis

Source^§	Original design	Country	Study size (n)		Mean age (years)	Male (%)	Mean follow-up (months)	Diseases at baseline	Outcomes	CRP sample collection	Adjustments	Quality problems^*
Source^§	Original design	Country	Participants	Cases	Mean age (years)	Male (%)	Mean follow-up (months)	Diseases at baseline	Outcomes	CRP sample collection	Adjustments	Quality problems^*
Apple 20075	Cohort	America	457	36	57	57	4	ACS	Death, F_CVD NF_CVD	3.1h^†	Age, sex, DM, renal disease	3^{a, b, e}
Bursi 20076	Cohort	America	329	75	69	52	12	AMI	HF, death	6.1h^†	Age, sex, comorbidity, peak cTnT, ECG, KC, MI, recurrent ischaemic events	2^{a, f}
Foussas 20077	Cohort	Greece	786	93	60.7	78.8	1	STEMI	Failed thrombolysis, F_CHD	3.5h^‡	Age, DM, anterior MI, Killip class, BP, HR, failed thrombolysis, cTnI	2^{b, c}
Foussas 20088,^B	Cohort	Greece	934	340	65.5	71.4	60	STEMI, NSTE-ACS	Death	4.3 h for STEMI, 8.7h for NSTE-ACS^‡	Age, sex, HBP, smoke, DM, angina, MI, angioplasty, CABG, HF, history of CVD or PAD, anterior STEMI, Killip class, time from index pain to treatment, cTnI, tHcy	1^c
Hartford 20079	Cohort	Sweden	757	166	65	73	75	ACS	Death	<24 h after admission	—	3^{c, e, f}
Jernberg 200410	Cohort	Sweden	726	161	70.4	33.2	40	NSTE-ACS	Death, MI	5.7 h^†	Age, DM, HBP, MI, HF, ECG, cTnT, NT-proBNP, cystatin C	2^{b, c}
Kavsak 200711	Cohort	Canada	446	—	64	59	96	ACS	Death, readmission for AMI or HF	3 h^†	Age, sex, cTnI	6^{a, b, c, d, e, f}
Kilcullen 200712,^A	Cohort	United Kindom	1448	296	72.5	61	12	ACS	Death	12–24 h^†	Age, HF, MI, HR, BP, ECG, Cr, inpatient PCI, H-FABP, cTnI	3^{c, e, f}
Kim 200613,^A	Cohort	Korea	215	24	65	65.1	8	ACS	Death, NF_CVD HF	Admission	Age, sex, NT-proBNP, cTnI, HBP, DM, smoke, HC, LVEF, diagnosis	2^{c, d}
Lindahl 200014	RCT^║	Sweden	917	124	70	65.3	37	Unstable CHD	Death	24 h^†	Age, sex, BMI, smoke, HBP, previous AMI, history of HF, DM, stable angina, stroke, number of drugs taking at admission, ECG, the index diagnosis, cTnT, fibrinogen level	1^c
Nikfardjam 200015	Cohort	Austria	729	118	61	75	36	AMI	F_CVD	Admission	Age, smoke, treatment, time from onset to admission, Cr kinase, DM, HC, HBP	3^{c, d, e}
Oldgren 200316	RCT^║	Sweden	320	22	66.5	—	1	UA, AMI	Death, MI	<24 h^†	—	6^{a, b, c, d, e, f}
Ray 200717,^B	RCT^║	America	2200	567	62.2	69.0	6	NSTE-ACS	Death, NF_MI	41 h^†	Age, sex, DM, smoke, HBP, MI, ECG, NSTEMI, prior revascularisation, medication, treatment	2^{a, c}
Sanchis 200418,^A	Cohort	Spain	665	45	66	74	6	AMI	Death	48 h after admission	Age, Killip class, HP, smoke, DM, previous ischaemic heart disease, ejection fraction	4^{a, b, c, d}
Scirica 200719	RCT^║	America	1992	185	61.1	12.8	10	ACS	Death, NF_CVD	40 h^†	Age, sex, BMI, DM, HC, MI, PAD, smoke, KC, treatment	4^{a, c, d, f}
Soeki 200220,^A	Cohort	Japan	92	10	66	77.2	50	MI	Death, NF_CVD	Admission	—	5^{a, c, d, e, f}
Suleiman 200621	Cohort	Israel	1044	194	61	72.3	23	AMI	Death, HF	12–24 h^†	Age, sex, Cr, HF, HBP, DM, smoke, MI, KC, HR, treatment, LVEF	0
Toss 199722	RCT^║	Sweden	965	138	70	65	5	Unstable CHD, MI	Death, MI	<72 h^†	—	3^{c, e, f}
Wollert 200723,^B	RCT^║	Germany	2081	143	66	63.2	12	NSTE-ACS	Death	<24 h^†	Age, sex, delay time, smoke, HBP, HC, DM, angina, MI, ECG revascularisation, HF	3^{a, d, f}
Zairis 200224	Cohort	Greece	319	52	60	73.7	22	STEMI	F_CHD	4.4 h^‡	Age, sex, DM, time from onset to treatment, STEMI, complete ST resolution, TIMI, LVEF	2^{b, d}

↵* The number of quality problems according to the six criteria, including sampling, study attrition, prognostic factor measurement, outcome measurement, confounding measurement and account, and analysis.25 ^aNo clear inclusion or exclusion criteria, or the settings of sampling were not described adequately; ^bno adequate collection or reporting of the information of participants who dropped out of the study; ^cno clear description or no blind operation of CRP measurement; ^dno clear definition of the outcome of interest or the outcome measurements were not valid and reliable; ^eno clear definition of the confounders or no (not all) important confounders were adjusted for; ^finsufficient data presentation or no appropriate strategy for model building.
↵† The median time from onset of symptoms to collection of blood samples.
↵‡ The mean time from onset of symptoms to administration of drugs. Blood samples for CRP measurements were obtained on admission and before the administration of any drugs.
↵§ Three kinds of studies were included in this meta-analysis: ^Astudies investigating the prognostic value of CRP by unit CRP; ^Bby a unit change of natural logarithmically transformed CRP, and otherwise, by CRP categories.
↵║ Articles were secondary-analyses of randomised controlled trials.
ACS, acute coronary syndrome; AMI, acute myocardial infarction; BMI, body mass index; BP, blood pressure; CABG, coronary artery bypass grafting; CHD, coronary heart disease; CK-MB, creatine phosphokinase isoenzyme MB; Cr, creatinine; CRP, C-reactive protein; cTnI, cardiac troponin I; cTnT, cardiac troponin T; CVD, cardiovascular disease; DM, diabetes mellitus; ECG, electrocardiogram; F_MI, F_CHD and F_CVD, fatal MI, CHD and CVD; HBP, high blood pressure; HC, hypercholesterolaemia; HF, heart failure; H-FABP, heart fatty acid-binding protein; HR, heart rate; KC, Killip class; LVEF, left ventricular ejection fraction; MI, myocardial infarction; NF_CHD, NF_CVD and NF_MI, non-fatal CHD, CVD and MI; NSTE-ACS, non–ST Elevation ACS; NT-proBNP, N-terminal pro-brain natriuretic peptide; PAD, peripheral arterial disease; PCI, percutaneous coronary intervention; RCT, randomised controlled trial; STEMI, ST-segment elevation myocardial infarction; TIMI, thrombolysis in myocardial infarction; tHcy, total homocysteine; UA, unstable angina.