Best practice in primary care pathology: review 3.

This best practice review examines four series of common primary care questions in laboratory medicine: (i) "minor" blood platelet count and haemoglobin abnormalities; (ii) diagnosis and monitoring of anaemia caused by iron deficiency; (iii) secondary hyperlipidaemia and hypertriglyceridaemia; and (iv) glycated haemoglobin and microalbumin use in diabetes. The review is presented in question-answer format, referenced for each question series. The recommendations represent a précis of guidance found using a standardised literature search of national and international guidance notes, consensus statements, health policy documents and evidence-based medicine reviews, supplemented by Medline Embase searches to identify relevant primary research documents. They are not standards, but form a guide to be set in the clinical context. Most of the recommendations are based on consensus rather than evidence. They will be updated periodically to take account of new information.

Iron deficiency anaemia in general practice: clinical outcomes over three years and factors influencing diagnostic investigations.

BACKGROUND: Iron deficiency anaemia (IDA) may be a sign of significant gastrointestinal disease, and delayed diagnosis may result in chronic morbidity. Studies in patients referred to hospital for investigation of their anaemia have shown that 5%-15% have a gastrointestinal cancer but there are few studies of patients presenting to primary care. Factors influencing further investigation in these patients have not previously been identified. PATIENTS AND METHODS: A cohort of patients presenting to their general practitioners (GPs) with IDA was identified and clinical outcomes recorded. Logistic regression was used to determine which factors influenced GPs to investigate the anaemia. RESULTS: 43% of patients had investigations within three months and serious pathology was found in 30% of these; 13% of patients were considered unfit for further investigation and 8% refused to have any. Independent predictors of non-investigation were a mild anaemia (odds ratio (OR) 0.38, confidence interval (CI) 0.23 to 0.61, p<0.001), female gender (OR 0.49, CI 0.3 to 0.8, p = 0.004), a previous history of anaemia (OR 0.39, CI 0.24 to 0.64, p<0.001), and age <65 years (OR 0.44, CI 0.26 to 0.74, p = 0.002). During the entire study period gastrointestinal cancer was diagnosed in 48 patients (11%); 17% of men had colorectal cancer. Of 263 patients alive at 12 months without a confirmed diagnosis, 113 (43%) had recurrent or persistent anaemia during the study period. CONCLUSION: Although the overall prevalence of gastrointestinal cancer in patients presenting to primary care is similar to that seen in secondary care, the diagnosis may be delayed due to lack of appropriate investigations resulting in significant morbidity.

Investigation and management of iron deficiency anaemia in general practice: a cluster randomised controlled trial of a simple management prompt.

BACKGROUND: Iron deficiency anaemia (IDA) remains the most common cause of anaemia and is frequently secondary to occult gastrointestinal blood loss requiring further investigation. The study was designed to prospectively assess the adequacy of investigation of IDA and to establish whether a simple computerised prompt would increase the completeness of investigation of patients presenting to their general practitioners. PATIENTS AND METHODS: All men aged >20 and women aged >50 newly found to have a probable IDA (n=431) in primary care were randomised according to general practice (n=89) to one of two computer generated prompts, by the haematology laboratories in two large district general hospitals. Data were collected 12 months after the index date. The primary outcome measure was the adequacy of investigation of the cause of anaemia. Multiple logistic regression was used to analyse each binary outcome. RESULTS: Two hundred and three (47%) of 431 patients presenting to their general practitioner with an IDA were adequately managed and 140/357 (39%) of patients who were otherwise fit for investigation had no tests at all. Twenty one (17%) of 125 patients who did have adequate investigation at the time of presentation were found to have colorectal cancer. Only 30% of patients had a confirmed diagnosis within 12 months. The prompt did not affect the level of investigation (odds ratio 0.88, 95% confidence interval (CI) 0.60 to 1.29, p=0.52). The initial prescribing of oral iron was improved (odds ratio 2.19, 95% CI 1.27 to 3.77, p=0.005), but not the documented prescribing of a full therapeutic course or the use of follow up blood counts. CONCLUSIONS: The investigation and management of IDA presenting in general practice remains inadequate and is not improved by a simple management prompt.

Audit of the investigation and outcome of iron-deficiency anaemia in one health district.

The investigation of iron-deficiency anaemia (IDA) is a clinical problem which arises in virtually all branches of medicine. To audit the investigation of IDA, a computer-based laboratory record system was used to identify all women over 50 years of age and all men (n = 200) presenting to a single district laboratory with probable IDA in a six-month period. In 21 of 130 incident cases anaemia was clearly attributable to non-gastrointestinal disease. Of the remaining 109, 19% had investigation of both upper and lower gastrointestinal tract, 21% the upper gastrointestinal tract only, and 7% the lower gastrointestinal tract only. In 55 cases either no investigation was performed or only faecal occult blood tests. Eighteen months after presentation nine colorectal cancers, five gastric cancers and 11 peptic ulcers had been diagnosed; 21 patients had died, including two from colorectal cancers not detected when the IDA presented. This audit has revealed substantial underinvestigation of probable IDA, with serious but treatable conditions remaining undetected. Our findings, which we have no reason to believe are unrepresentative, indicate that policies are needed to ensure adequate investigation of IDA.

Sulphasalazine associated pancytopenia may be caused by acute folate deficiency.

Agranulocytosis and aplastic anaemia associated with sulphasalazine are well recognised, but pancytopenia caused by acute megaloblastic arrest of haemopoiesis while taking sulphasalazine has not previously been described. We report three patients who, after taking sulphasalazine for over two years, suddenly developed severe pancytopenia with gross megaloblastic changes in the marrow. In two patients there was a good response to high dose oral folic acid but the third required folinic acid. The mechanism appears to be acute folate deficiency, and the requirement for folinic acid in one case suggests that the known inhibition of folate metabolism by sulphasalazine also contributes. The syndrome appears to be associated with high dosage and slow acetylator status. The drug has been successfully restarted at reduced dosage with folate supplements in two patients both of whom were slow acetylators. In the third case, whose acetylator status is not known, progression of her disease led to colectomy.