Studies giving a PPV of ≥5% in one or more strata of iron deficiency anaemia for colorectal cancer or a predictive value of <5% in an equivalent stratum.
| Stratification with PPV | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Study and NOQAS star rating | Type | Data source | Follow-up | Age, years | Sex | Symptom | Sex | Age, years | Number with symptom | PPV, % (95% CI) | ||
| Stellon et al, 199727 (6 stars) | Prospective cohort | Specifically registered | Not given | >50 | M+F | Hb <12.0 and/or MCV<80 with ferritin ≤16 | M+F | >50 | 26 | 7.7 (2.1 to 24.1) | ||
| Yates et al, 200428 (6 stars) | Retrospective cohort | Routinely recorded data | 1 year | >20 | M | Hb ≤12 MCV <hospital normal range, RBC <5.5 | M | >20 | 154 | 17.5 (12.3 to 24.3) | ||
| >50 | F | Hb ≤11 MCV <hospital normal range, RBC <5.5 | F | >50 | 277 | 3.2 (1.7 to 6.1) | ||||||
| Hamilton et al, 200829 (9 stars) | Case-control | Routinely recorded electronic data | NA | ≥30 | M+F | Hb 11.0–11.9 with indicators of iron deficiency | M | 60–69 | Not given | 6.5 (2.0 to 19) | ||
| Hb <11.0 with indicators of iron deficiency | M | ≥60 | Not given | All age bands and Hb levels PPV >5 (range 5.5 to ≥31) | ||||||||
| F | 70–79 | Not given | All Hb levels PPV >5 (range 5.9 to 10) | |||||||||
| Hb <10.0 with indicators of iron deficiency | F | ≥80 | Not given | All Hb levels PPV >5 (range 5.7 to 10%) | ||||||||
| Hb <9.0 with indicators of iron deficiency | F | 60–69 | Not given | >5 (likelihood ratio) | ||||||||
F = female. Hb = haemoglobin (g dl-1). M = male. MCV = mean corpuscular volume (fL). NA = not applicable. NOQAS = Newcastle-Ottawa Quality Assessment Scales. PPV = positive predictive value. RBC = red blood corpuscles.