[Prospective comparison of the flow chart for laboratory investigations for anaemia from the Dutch College of General Practitioners' guideline 'Anaemia' with a self-developed, substantive and logistical alternative flow chart].

Objective: To compare the flow diagram for the diagnosis of anaemia from the guideline 'Anaemia' from the Dutch College of General Practitioners (NHG) with a substantive and logistical alternative protocol.

Design: Prospective.

Method: For evaluation of anaemia, 124 patients from primary care reported to the laboratories of the St. Elisabeth Hospital in Tilburg (n = 94) and the Scheper Hospital in Emmen (n = 30), the Netherlands. Two flow charts were used: the NHG's flow chart and a self-developed chart in which not mean corpuscular volume, but ferritin concentration occupies the central position. All the laboratory tests mentioned in both flow charts were carried out in every patient with, for practical reasons, the exception of Hgb electrophoresis and bone marrow investigations. General practitioners were approached and patient dossiers were consulted to obtain further clinical data.

Results: According to the NHG protocol, on the grounds of the laboratory investigations, 64 (52%) of patients could not be put in a specific category. The majority were patients with normocytary anaemia who did not fulfil the criteria for iron deficiency anaemia or the anaemia of chronic disease. According to the alternative chart, in 36 (29%) patients no diagnosis was made. These were patients in whom no abnormal laboratory findings were observed, other than low haemoglobin values. The majority of the patients had normocytary anaemia, in some cases this was interpreted as the anaemia of chronic disease, but more often the anaemia could not be assigned to a particular category. A large number ofpatients had a raised creatinine value. This value did not appear in the NHG protocol. In 15% of patients, more than one cause for anaemia was found. The NHG protocol did not enable these multiple diagnoses to be made. Accordingly, the NHG protocol was difficult to implement in the laboratory.

Conclusion: Using the NHG flow diagram a large percentage of patients could not be assigned to a particular category. Using the alternative flow diagram, which procedure is easier to carry out in the laboratory, it was possible to make multiple diagnoses.