Three studies (7,315 participants) that assessed the diagnostic performance of transferrin saturation and serum ferritin levels for the identification of haemochromatosis were included in the review. One retrospective cohort (158 participants) and one before-and-after study (251 participants), both assessing the effectiveness of phlebotomy for the treatment of haemochromatosis, were also included in the review.
Data on the diagnostic performance of transferrin saturation and serum ferritin were very limited; studies varied with respect to the reference standard of diagnosis, reported no data on test-negative patients, and not all patients with values over the threshold underwent further assessment. It was therefore not possible to derive estimates of sensitivity and specificity.
Effectiveness of phlebotomy.
No randomised trials of therapeutic phlebotomy were identified. A retrospective cohort study reported greater estimated Kaplan-Meier survival for patients who were adequately phlebotomised compared with those who were not (93% versus 48% at 5 years, and 78% versus 32% at 10 years), but the clinical comparability of the patient groups could not be determined. A before-and-after study reported improved liver histology in 42 out of 185 patients after phlebotomy (deterioration was reported in 2 patients); biopsy sampling error was a potential concern in this study
Effectiveness of screening.
Given the lack of evidence on the effectiveness of therapeutic phlebotomy, the effectiveness of screening in primary care could not be directly assessed.