Investigations

• blood count ^c
• ESR ^c

Why?

An elevated platelet count can help diagnose inflammatory bowel disease

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability	LR- (95% CI)	Post-test Probability
inflammatory bowel disease c   (pre-test probability: 11%)	inflammatory bowel disease   (endoscopy or histology)	anaemia (Hb < 12 g/dl in women, < 14 g/dl in men)	2.7 (1.8 to 4.0)	25%	0.52 (0.33 to 0.83)	6%
		white cell count > 10 x 109/l	2.2 (1.5 to 3.3)	22%	0.59 (0.39 to 0.91)	7%
		platelet count > 450 x 109/l	42 (13 to 130)	84%	0.41 (0.26 to 0.65)	5%
		ESR > 30 mm/h	1.9 (1.3 to 2.6)	21%	0.71 (0.50 to 0.995)	8%