Table 3.

Characteristic and accuracy of selected fecal occult blood test studies.

No	Author (Year)	Country	Study design	Study population	Index test	Reference test	Sample size	Sensitivity %	Specificity %	PPV %	NPV %	Accuracy %
1.	Shapiro et al. (2017) [29]	USA	Cross-sectional	Asymptomatic patients from clinics, aged 50–75 years.	HS-gFOBT	Not mentioned	1095	7.4	98.6	23.6		86.0*
2.	Mario et al. (2015) [30]	Brazil	Cross-sectional	Asymptomatic patients, aged ≥ 50 years.	gFOBT & flexible RSS	Colonoscopy	102	30.0	92.4	30.0*	5.0*	86.3*
3.	Elsafi et al. (2015) [31]	Saudi Arabia	Cohort	Asymptomatic patients aged 50–74 years old from 2 hospitals and confirmed CRC patients.	gFOBT		Cases 257 Control 20	50.0	77.9	3.5	99.0	71.8*
4.	Lohsiriwat et al. (2014) [32]	Thailand	Case-control	Histologically proven adenocarcinoma of the colon and rectum patients and individuals with normal colonoscopic findings.	FOBT	Colonoscopy	Cases 96 Control 101	41.0	97.0	93.0	63.0	70.0
5.	Redwood et al. (2014) [33]	USA	Cross-sectional	Asymptomatic adults aged ≥ 40 years.	gFOBT	Colonoscopy	304	28.5	75.7	10.6	91.3	71.4*
6.	Yeasmin et al. (2013) [34]	Bangladesh	Cross-sectional	Patients suspected to have occult bleeding.	gFOBT	Colonoscopy	110	75.0	21.6	7.0	91.7	25.5*

FOBT- Fecal occult blood test.

gFOBT- Guaiac fecal occult blood test.

HG-gFOBT- High-sensitivity guaiac fecal occult blood test.

RSS- Recto sigmoidoscopy.

PPV- Positive Predictive Value.

NPV- Negative Predictive Value.

* indirectly calculated from data.