Initial study of anaemia profile for primary care centres with automated laboratory algorithms reduces the demand for ferritin, iron, transferrin, vitamin B12 and folate tests

AIM

To evaluate the influence of an algorithm designed to incorporate reflex testing according to haemogram results for analytical tests ordered to investigate anaemia.

METHODS

In 2020, a new request for 'initial study of anaemia' was created in three primary care pilot centres for suspected anaemia or new anaemias. A haemogram was ordered and the remainder of the tests were created in a reflex manner according to an algorithm integrated in the laboratory information system that also generates a comment that is completed and validated by a haematologist. The demand for tests was evaluated over three time periods.

RESULTS

Of 396 requests, anaemia was detected in 80 (20.2%), with 26 microcytic anaemias (6.57%), 20 iron deficiency anaemias, 41 (10.3%) normocytic anaemias and 13 macrocytic anaemias (3.28%); 4 with folate deficiency; and 1 haemolytic anaemia. No haematological diseases were detected. Twenty-four (6.06%) cases exhibited microcytosis/hypochromia without anaemia, 12 of which exhibited iron deficiency. Four young women exhibiting within-limit haemoglobin levels had iron deficiency. There were 56 (14.1%) cases of macrocytosis without anaemia.With the new profile of 'initial study of anaemia', the demand for tests was reduced and was significantly lower than in the remainder of primary centres for iron, transferrin, ferritin, vitamin B₁₂ and folate.

CONCLUSIONS

A new profile of 'initial study of anaemia' in the request form with algorithms integrated in the laboratory information system enabled submission of orders and decreased the demand for unnecessary iron, transferrin, ferritin, vitamin B₁₂ and folate tests.

A new diagnostic work-up for defining anemia etiologies: a cohort study in patients ≥ 50 years in general practices

Background

To study etiologies of anemia using an extensive laboratory analysis in general practices.

Method

An extensive laboratory analysis was performed in blood of newly diagnosed anemia patients aged ≥50 years from the general population in the city of Dordrecht area, the Netherlands. Eight laboratory-orientated etiologies of anemia were defined. Patients were assigned one or more of these etiologies on the basis of their test results.

Results

Blood of 4152 patients (median age 75 years; 49% male) was analyzed. The anemia etiology was unclear in 20%; a single etiology was established in 59%; and multiple etiologies in 22% of the patients. The most common etiologies were anemia of chronic disease (ACD) (54.5%), iron deficiency anemia (IDA) (19.1%) and renal anemia (13.8%). The most common single etiologies were IDA (82%) and ACD (68%), while the multiple etiologies most commonly included folic acid deficiency (94%) and suspected bone marrow disease (88%). Older age was associated with a lower incidence of IDA and a higher incidence of renal anemia. Mild anemia was more often associated with ACD and uncertain anemia, while severe anemia was mainly seen in patients with IDA.

Conclusion

Extensive laboratory analysis in anemic patients from the general population helped clarify the etiology of anemia and revealed many various combinations of etiologies in a significant proportion of patients. Age, sex and the severity of anemia are predictive of the underlying etiology.

Preventing overuse of laboratory diagnostics: a case study into diagnosing anaemia in Dutch general practice

Background

More information is often thought to improve medical decision-making, which may lead to test overuse. This study assesses which out of 15 laboratory tests contribute to diagnosing the underlying cause of anaemia by general practitioners (GPs) and determines a potentially more efficient subset of tests for setting the correct diagnosis.

Methods

Logistic regression was performed to determine the impact of individual tests on the (correct) diagnosis. The statistically optimal test subset for diagnosing a (correct) underlying cause of anaemia by GPs was determined using data from a previous survey including cases of real-world anaemia patients.

Results

Only 9 (60%) of the laboratory tests, and patient age, contributed significantly to the GPs’ ability to diagnose an underlying cause of anaemia (CRP, ESR, ferritin, folic acid, haemoglobin, leukocytes, eGFR/MDRD, reticulocytes and serum iron). Diagnosing the correct underlying cause may require just five (33%) tests (CRP, ferritin, folic acid, MCV and transferrin), and patient age.

Conclusions

In diagnosing the underlying cause of anaemia a subset of five tests has most added value. The real-world impact of using only this subset should be further investigated. As illustrated in this case study, a statistical approach to assessing the added value of tests may reduce test overuse.

Long-term outcomes in patients newly diagnosed with iron deficiency anaemia in general practice: a retrospective cohort study

OBJECTIVES

To describe all iron deficiency anaemia (IDA)-related causes during follow-up of patients newly diagnosed with IDA and to assess whether a delayed colorectal cancer (CRC) diagnosis influences survival.

DESIGN AND SETTING

Retrospective cohort study of patients from general practices in the Dordrecht area, the Netherlands.

PARTICIPANTS

Men and women aged ≥50 years with a new diagnosis of IDA (ie, no anaemia 2 years previously).

METHOD

From February 2007 to February 2018, all relevant data were collected from the files of the referral hospital. Early IDA-related cause was defined as established within 18 weeks after IDA diagnosis. Cox proportional-hazards regression was used to analyse survival of patients with CRC diagnosis.

RESULTS

587 patients with IDA were included with a median follow-up of 4.6 years. Early and late IDA-related causes could be established in 32% and 8% of patients, respectively. Early and late CRC was found in 8% and 2% of patients, respectively, and were located mainly right sided. After adjustment for age, gender and TNM classification, mortality risk was lower in patients with IDA with early CRC diagnosis, but not significantly (HR 0.30, 95% CI 0.09 to 1.02).

CONCLUSION

Even with extended follow-up, the cause of IDA remains elusive in the majority of patients with IDA in general practice. However, patients with IDA are at increased risk for in particular right-sided CRC and a late diagnosis of CRC appears to have a detrimental effect on survival in patients with IDA.

Assessing the cost-effectiveness of a routine versus an extensive laboratory work-up in the diagnosis of anaemia in Dutch general practice

Background Establishing the underlying cause of anaemia in general practice is a diagnostic challenge. Currently, general practitioners individually determine which laboratory tests to request (routine work-up) in order to diagnose the underlying cause. However, an extensive work-up (consisting of 14 tests) increases the proportion of patients correctly diagnosed. This study investigates the cost-effectiveness of this extensive work-up. Methods A decision-analytic model was developed, incorporating all societal costs from the moment a patient presents to a general practitioner with symptoms suggestive of anaemia (aged ≥ 50 years), until the patient was (correctly) diagnosed and treated in primary care, or referred to (and diagnosed in) secondary care. Model inputs were derived from an online survey among general practitioners, expert estimates and published data. The primary outcome measure was expressed as incremental cost per additional patient diagnosed with the correct underlying cause of anaemia in either work-up. Results The probability of general practitioners diagnosing the correct underlying cause increased from 49.6% (95% CI: 44.8% to 54.5%) in the routine work-up to 56.0% (95% CI: 51.2% to 60.8%) in the extensive work-up (i.e. +6.4% [95% CI: -0.6% to 13.1%]). Costs are expected to increase slightly from €842/patient (95% CI: €704 to €994) to €845/patient (95% CI: €711 to €994), i.e. +€3/patient (95% CI: €-35 to €40) in the extensive work-up, indicating incremental costs of €43 per additional patient correctly diagnosed. Conclusions The extensive laboratory work-up is more effective for diagnosing the underlying cause of anaemia by general practitioners, at a minimal increase in costs. As accompanying benefits in terms of quality of life and reduced productivity losses could not be captured in this analysis, the extensive work-up is likely cost-effective.