Clinical pallor is useful to detect severe anemia in populations where anemia is prevalent and severe

Examining different cost ratio frameworks for decision rule machine learning algorithms in diagnostic application

BACKGROUND

Artificial Intelligence (AI) plays a pivotal role in the diagnosis of health conditions ranging from general well-being to critical health issues. In the realm of health diagnostics, an often overlooked but critical aspect is the consideration of cost-sensitive learning, a facet that this study prioritizes over the non-invasive nature of the diagnostic process whereas the other standard metrics such as accuracy and sensitivity reflect weakness in error profile.

OBJECTIVE

This research aims to investigate the total cost of misclassification (Total Cost) by decision rule Machine Learning (ML) algorithms implemented in Java platforms such as DecisionTable, JRip, OneR, and PART. An augmented dataset with conjunctiva images along candidates' demographic and anthropometric features under supervised learning is considered with a specific emphasis on cost-sensitive classification.

METHODS

The opted decision rule classifiers use the text features, additionally the image feature 'a* value of CIELAB color space' extracted from the conjunctiva digital images as input attributes. The pre-processing consists of amalgamating text and image features on a uniform scale, normalizing. Then the 10-fold cross-validation enables the classification of samples into two categories: the presence or absence of the anemia. This study utilizes the Cost Ratio (ρ) extracted from the cost matrix to meticulously monitor the Total Cost in four different cost ratio methodologies namely Uniform (U), Uniform Inverted (UI), Non-Uniform (NU), and Non-Uniform Inverted (NUI).

RESULTS

It has been established that the PART classifier stands out as the top performer in this binary classification task, yielding the lowest mean total cost of 629.9 compared to other selected classifiers. Moreover, it demonstrates a comparatively lower standard deviation 335.9, and lower total cost across all four different cost ratio methodologies. The ranking of algorithm performance goes as follows: PART, JRIP, DecisionTable, and OneR.

CONCLUSION

The significance of adopting a cost-sensitive learning approach is emphasized showing the PART classifier's consistent performance within the proposed framework for learning the anemia dataset. This emphasis on cost-sensitive learning not only enhances the recommendations in diagnosis but also holds the potential for substantial cost savings and makes it a noteworthy focal point in the advancement of AI-driven health care.

Improving Anemia Assessment in Clinical and Public Health Settings

We aim to provide a practical approach to assess anemia and its primary causes, both in clinical settings and in the context of public health programs. Anemia remains a global challenge; thus, to achieve goals for anemia reduction and assess progress, standardized approaches are required for the assessment of anemia and its causes. We first provide a brief review of how to assess anemia, based on hemoglobin concentrations and cutoffs that correspond to age, sex, and physiologic status. Next, we discuss how to assess the likely causes of anemia in different settings. The causes of anemia are classified as non-nutritional (for example, because of infection, inflammation, blood loss, or genetic disorders) or nutrition-specific (for example, because of deficiencies of iron, vitamin A, riboflavin, vitamin B12, or folate). There is an important overlap between these 2 categories, such as the increased likelihood of iron deficiency in the context of inflammation. Given the multifaceted nature of anemia etiology, we introduce a framework for anemia assessment based on the "ecology of anemia," which recognizes its many overlapping causes. This conceptual framework is meant to inform what data on anemia causes may need to be collected in population surveys. The framework has a supporting table with information on the diagnostic tests, biomarkers and proposed cutoffs, characteristics, and feasibility of collecting the myriad information that can help elucidate the anemia etiology. We also provide examples of how this framework can be applied to interpret the anemia risk factor data from population-based surveys that can inform decisions about context-specific interventions. Finally, we present research gaps and priorities related to anemia assessment.

Diagnosing anemia: Challenges selecting methods, addressing underlying causes, and implementing actions at the public health level

Accurate and affordable tools for diagnosing anemia and its main determinants are essential for understanding the magnitude and distribution of the problem and the appropriate interventions needed for its timely prevention and treatment. The objective of this review is to address methods, equipment, and sample-related and quality control aspects of hemoglobin measurement for anemia diagnosis. Also, other iron-, infectious-, and genetic-related causes of anemia are addressed in individuals and populations. The best practice for hemoglobin determination is the use of venous blood, analyzed on automated hematology analyzers, with high-quality control measures in place. The importance of a correct anemia diagnosis is highlighted by the cost of a misdiagnosis. A false-negative diagnosis may result in missing out and not treating anemia, its causes, and its adverse effects. On the other hand, a false-positive diagnosis may result in the provision of unneeded treatment or referral for expensive laboratory tests to determine a cause of anemia, wasting valuable resources and risking causing harm. At the individual level, clinicians must understand the causes of absolute and functional anemia to diagnose and treat anemia at the clinical level. Actions toward anemia diagnosis and control at public health levels require global, regional, and country actions that should cover general and context-specific characteristics.

An intelligent non-invasive system for automated diagnosis of anemia exploiting a novel dataset

Anemia is a condition in which the oxygen-carrying capacity of red blood cells is insufficient to meet the body's physiological needs. It affects billions of people worldwide. An early diagnosis of this disease could prevent the advancement of other disorders. Traditional methods used to detect anemia consist of venipuncture, which requires a patient to frequently undergo laboratory tests. Therefore, anemia diagnosis using noninvasive and cost-effective methods is an open challenge. The pallor of the fingertips, palms, nail beds, and eye conjunctiva can be observed to establish whether a patient suffers from anemia. This article addresses the above challenges by presenting a novel intelligent system, based on machine learning, that supports the automated diagnosis of anemia. This system is innovative from different points of view. Specifically, it has been trained on a dataset that contains eye conjunctiva photos of Indian and Italian patients. This dataset, which was created using a very strict experimental set, is now made available to the Scientific Community. Moreover, compared to previous systems in the literature, the proposed system uses a low-cost device, which makes it suitable for widespread use. The performance of the learning algorithms utilizing two different areas of the mucous membrane of the eye is discussed. In particular, the RUSBoost algorithm, when appropriately trained on palpebral conjunctiva images, shows good performance in classifying anemic and nonanemic patients. The results are very robust, even when considering different ethnicities.

Anemia among Syrian Refugee Children Aged 6 to 23 Months Living in Greater Beirut, Lebanon, including the Voices of Mothers' and Local Healthcare Staff: A Mixed-Methods Study

Globally, the prevalence of anemia among children during the period of complementary feeding is high. A cross-sectional, mixed-methods study was conducted to examine the main determinants of anemia among Syrian refugee children aged 6 to 23 months (n = 215) and to illuminate the knowledge, attitudes and perceptions of their mothers and Lebanese healthcare staff on its causes and available treatment options. 42% of the children and 20% of their mothers were anemic. Determinants of child anemia were the mother having anemia or not knowing that fish/seafood is a source of iron; the child having been acutely ill the last two weeks or receiving cow's milk, but not consuming iron-rich infant formula, added fats/oils, or fruits in the previous 24 hours. Several Syrian mothers knew some causes of anemia and named dizziness as a leading symptom but did not mention flesh foods as a key source of heme iron. They reported financial constraints in accessing iron-rich foods and supplements. Lebanese doctors largely gave appropriate dietary advice and prescribed iron supplements as treatment. Multisectoral interventions are needed that combine medical and financial support with nutrition counseling for mothers to reduce the high burden of anemia among young children living in a multiple crises situation.

Progressive evaluation in spectroscopic sensors for non-invasive blood haemoglobin analysis - a review

Frequent monitoring of haemoglobin concentration is highly recommended by physicians to diagnose anaemia and polycythemia Vera. Moreover, Some other conditions also demand assessment of haemoglobin, and these conditions are blood loss, before blood donation, during pregnancy, preoperative, perioperative and postoperative conditions. Cyanmethaemoglobin/haemiglobincyanide method, portable haemoglobinometers and haematology analyzers are few standard methods to diagnose mentioned ailments. However, discomfort, delay and risk of infection are typical limitations of traditional measuring solutions. These limitations create the necessity to develop a non-invasive haemoglobin monitoring technique for a better lifestyle. Various methods and products are already developed and popular due to their non-invasiveness; however, invasive solutions are still considered as the reference standard method. Therefore, this review summarizes the attributes of existing non-invasive solutions. These attributes are finalized as brief details, accuracy, optimal benefits, and research challenges for exploring potential gaps, advancements and possibilities to consider as futuristic alternative methodologies. Non-invasive total haemoglobin assessing techniques are mainly based on optical spectroscopy (reflectance/transmittance) or digital photography or spectroscopic imaging in spot check/continuous monitoring mode. In all these techniques, we have noticed that there is a need to consider different light conditions, motion artefacts, melanocytes, other blood constituents, smoking and precise fixing of the sensor from the sensing spot for exact formulation. Moreover, based on careful and critical analysis of outcomes, none of these techniques or products is used independently or intended to replace invasive laboratory testing. Therefore there is a requirement for a more accurate technique that can eliminate the requirement of blood samples and likely end up as a reference standard method.

Prevalence of anemia and associated risk factors among pregnant women in an urban community at the North of Saudi Arabia

BACKGROUND

Anemia in pregnancy is common public health problem with poor outcome for both mother and child. This study, aimed to determine the prevalence of anemia and its associated factors among pregnant women in an urban community at the north of Saudi Arabia.

MATERIALS AND METHODS

A cross-sectional study was carried out among 390 pregnant attending for antenatal care in one of eight Primary Health Care (PHC) centers in Hail city, Saudi Arabia.

RESULTS

Among participants, 133 (34.1%) were anemic (hemoglobin level < 11 g/dl). Out of which, 24.9% were mildly anemic, 9.2% were moderately anemic and none of the participant was found to be severely anemic. The prevalence of anemia increased significantly with low income (p = 0.026), bigger family size (p = 0.020), higher parity (p = 0.023), longer menstrual cycle > 5 days (p = 0.042), bleeding during pregnancy (p = 0.028), infrequent intake of meat (p = 0.020), the habit of drinking tea just after meals (p = 0.019), past history of anemia (p < 0.001), clinical anemia (pallor) (p < 0.001). On the other hand, increased BMI (p = 0.002) and frequent intake of food from restaurants (p = 0.008) were found to be negatively associated with anemia among pregnant women.

CONCLUSION

"In urban Hail region, Saudi Arabia, anemia among pregnant women was a moderate public health problem. Low income, bigger family size, higher parity, longer menstrual cycle > 5 days, bleeding during pregnancy, infrequent intake of meat, the habit of drinking tea just after meals, past history of anemia, and the sign of clinical anemia (pallor), were found to be significantly associated with anemia. These findings give insight to healthcare providers about the importance of early detection and management of anemia in early pregnancy. Further research utilizing prospective cohort design to study risk factors of anemia including rural areas, should be considered to support and extend the present study findings".

Emerging point-of-care technologies for anemia detection

Anemia, characterized by low blood hemoglobin level, affects about 25% of the world's population with the heaviest burden borne by women and children. Anemia leads to impaired cognitive development in children, as well as high morbidity and early mortality among sufferers. Anemia can be caused by nutritional deficiencies, oncologic treatments and diseases, and infections such as malaria, as well as inherited hemoglobin or red cell disorders. Effective treatments are available for anemia upon early detection and the treatment method is highly dependent on the cause of anemia. There is a need for point-of-care (POC) screening, early diagnosis, and monitoring of anemia, which is currently not widely accessible due to technical challenges and cost, especially in low- and middle-income countries where anemia is most prevalent. This review first introduces the evolution of anemia detection methods followed by their implementation in current commercially available POC anemia diagnostic devices. Then, emerging POC anemia detection technologies leveraging new methods are reviewed. Finally, we highlight the future trends of integrating anemia detection with the diagnosis of relevant underlying disorders to accurately identify specific root causes and to facilitate personalized treatment and care.

Point-of-care haemoglobin testing in African hospitals: a neglected essential diagnostic test

Owing to the rapid turnaround time in the assessment of haemoglobin level by point-of-care tests (POC Hb), these have grown in popularity and scope in large parts of the world. However, whilst POC testing for malaria and HIV remains has been integrated into patient management in Africa, the use of POC haemoglobin testing remains neglected by health services. The main users of transfusions (paediatric, maternity and trauma services) present largely as emergencies. Ward-based POC Hb could result in more rapid and accurate diagnosis of anaemia, contributing to saving of lives and at the same time reduce unnecessary transfusions which deplete the limited supplies of donated blood in Africa. Severe anaemia requiring transfusion is a major cause of paediatric admission in Africa. At a dissemination meeting to discuss the results of a large phase III paediatric transfusion trial and steps to implementation of the findings participants strongly recommended that one of the most pressing actions required was to prioritise the use of POC haemoglobin testing. This would facilitate implementation of the new transfusion algorithm, developed at the meeting, which refines patient management including blood transfusions. We present the rationale for the strongly recommended prioritisation of POC Hb, using paediatric transfusion as an exemplar.

Semantic Segmentation of Conjunctiva Region for Non-Invasive Anemia Detection Applications

Technology is changing the future of healthcare, technology-supported non-invasive medical procedures are more preferable in the medical diagnosis. Anemia is one of the widespread diseases affecting the wellbeing of individuals around the world especially childbearing age women and children and addressing this issue with the advanced technology will reduce the prevalence in large numbers. The objective of this work is to perform segmentation of the conjunctiva region for non-invasive anemia detection applications using deep learning. The proposed U-Net Based Conjunctiva Segmentation Model (UNBCSM) uses fine-tuned U-Net architecture for effective semantic segmentation of conjunctiva from the digital eye images captured by consumer-grade cameras in an uncontrolled environment. The ground truth for this supervised learning was given as Pascal masks obtained by manual selection of conjunctiva pixels. Image augmentation and pre-processing was performed to increase the data size and the performance of the model. UNBCSM showed good segmentation results and exhibited a comparable value of Intersection over Union (IoU) score between the ground truth and the segmented mask of 96% and 85.7% for training and validation, respectively.

Estimate of Anemia with New Non-Invasive Systems—A Moment of Reflection

Anemia is a global public health problem with major consequences for human health. About a quarter of the world population shows a hemoglobin concentration that is below the recommended thresholds. Non-invasive methods for monitoring and identifying potential risk of anemia and smartphone-based devices to perform this task are promising in addressing this pathology. We have considered some well-known studies carried out on this topic since the main purpose of this work was not to produce a review. The first group of papers describes the approaches for the clinical evaluation of anemia focused on different human exposed tissues, while we used a second group to overview some technologies, basic methods, and principles of operation of some devices and highlight some technical problems. Results extracted from the second group of papers examined were aggregated in two comparison tables. A growing interest in this topic is demonstrated by the increasing number of papers published recently. We believe we have identified several critical issues in the published studies, including those published by us. Just as an example, in many papers the dataset used is not described. With this paper we wish to open a discussion on these issues. Few papers have been sufficient to highlight differences in the experimental conditions and this makes the comparison of the results difficult. Differences are also found in the identification of the regions of interest in the tissue, descriptions of the datasets, and other boundary conditions. These critical issues are discussed together with open problems and common mistakes that probably we are making. We propose the definition of a road-map and a common agenda for research on this topic. In this sense, we want to highlight here some issues that seem worthy of common discussion and the subject of synergistic agreements. This paper, and in particular, the discussion could be the starting point for an open debate about the dissemination of our experiments and pave the way for further updates and improvements of what we have outlined.

Potential new tool for anemia screening: An evaluation of the performance and usability of the TrueHb Hemometer

In low- and middle-income countries, many women experience anemia during pregnancy due to insufficient dietary intake of key micronutrients, parasitic infections, hemoglobinopathies, and chronic infections. Maternal anemia increases perinatal risks for both mothers and infants, and slow progress to reduce the prevalence may be due in part to the lack of affordable tools to quantify hemoglobin levels in antenatal care (ANC) clinics. A simple, inexpensive, accurate, and robust diagnostic is needed to measure hemoglobin in ANC. This study evaluated the performance and usability of the TrueHb Hemometer. A cross-sectional diagnostic accuracy study was conducted to compare the accuracy of the TrueHb and the HemoCue® 201+ using capillary samples. Next, analytical performance (precision, coefficient of variation, R²) of the TrueHb was evaluated in varying environmental conditions using linearity panels with serial dilutions of venous blood samples. Lastly, the usability of the TrueHb Hemometer was assessed across three domains (effectiveness, efficiency, and satisfaction) by 20 ANC providers in Ghana. Capillary blood test results were not well correlated (R² = 0.35) between the TrueHB and HemoCue201+, but 80% of TrueHb measurements were within +/-1.0 g/dl of the HemoCue® 201+ hemoglobin values. Precision tests indicated similar mean values across the three environmental conditions (CV<6%). At 21°C, the TrueHb follows a linear relationship (R²≥0.96) but does not generate accurate readings below 4.0 g/dl. At 30°C and 37°C, the TrueHb follows a linear relationship (R² > 0.90) but begins to underestimate the hemoglobin concentration below 7.0 g/dl. The usability study identified potential failure modes due to inadequate instructions and device feedback. With some modifications, both to the product and to the instructions for use, the TrueHb may be suitable for use in ANC settings to help fill the diagnostic gap for anemia screening during pregnancy. Further testing is required with anemic populations in LMIC settings.

Parental Perception of Childhood Anaemia and Efficiency of Instrument Assisted Pallor Detection among Mothers in Southeast Nigeria: A Field Validation Study

Background

Control of anemia can be achieved with early detection of pallor by parents at home. However, most parents lack the capacity to recognize pallor; thus most cases of anaemia are detected during hospital visit due to other symptoms. This study aimed to evaluate parental ability to detect pallor when aided with the anaemia screening tool.

Methods

In the study information on the symptoms of illness and parental knowledge on anaemia. Their ability to detect anaemia aided with the Home-Base anaemia-screen tool (HB-Anae) was compared to the healthcare providers' assessment of pallor. The haemoglobin estimation with the Hb-301 haemoglobinometer was used as the gold standard.

Results

None of the children in their previous illnesses had paleness as a complaint. Few (20.8%) parents knew what anaemia meant. Only 18.3% knew sites on the body where pallor can be detected. Many (55.1%; 304/552) surveyed children were anaemic (Hb<11g/dl) based on HB 301. Majority (88.8%; 270/304) of the parents aided with the HB-Anae were able to detect pallor on the children who were anaemic compared to 95.1% (289/304) detected by healthcare workers unaided, and the difference was not statistically significant (p=0.25).

Conclusion

There was poor knowledge on anaemia among parents. The ability of parents to detect anaemia could be improved with the simple HB-Anae screen tool.

Evaluation of the Performance of Haemoglobin Colour Scale and Comparison with HemoCue Haemoglobin Assay in Diagnosing Childhood Anaemia: A Field Validation Study

BACKGROUND

Anaemia in children has high mortality. We present the results of assessment of the accuracy of Haemoglobin Colour Scale in identifying anaemia compared with HemoCue assay.

METHODS

The presence of anaemia in 524 children from four communities was screened using the Haemoglobin Colour Scale (HCS) and HemoCue assay. Independent healthcare providers that estimated the haemoglobin level using Hb-301 haemoglobinometer were different from those that read the colour scale. The sensitivity, specificity, positive predictive value, and negative predictive value were estimated.

RESULTS

Of the 524 children surveyed, 44.5% (233/524), 50% (262/524), and 32.2% (168/524) were found to be anaemic using the HemoCue, HCS (p= 0.25), and clinical pallor (p=0.03) respectively. Using the HemoCue as standard, the sensitivity of the HCS and clinical pallor was 89.1% and 72.1%, respectively, and specificity 90.2% and 84.6%, respectively. 74.7 % of the colour scale result was within the 1.0g/dl of the HemoCue reading and 23 % was within 2.0g/dl.

CONCLUSION

The HCS can improve the ability to detect anaemia especially where the use of the HemoCue is not feasible as in the resource poor countries. However, every case of anaemia requires further investigation to determine the underlying causes.

A disease burden analysis of garment factory workers in Bangladesh: proposal for annual health screening

Background

To characterize the health status of selected garment and textile factory workers in Bangladesh using a workplace mobile health clinic.

Methods

A retrospective review of de-identified worker health information was performed using 1906 medical records.

Results

The mean age of the workers was 27.9±7.3 y, with 60.3% (1150/1906) female and 39.7% (756/1906) male workers. The most common medical conditions identified were anemia (19.0%; 362/1906), elevated BP (EBP) (11.9%; 226/1906) and elevated fasting blood glucose (FBG) (8.0%; 151/1906). Among the workers who had EBP, 86.3% (195/226) were previously undiagnosed, while out of the workers with elevated FBG, 72.8% (110/151) were newly diagnosed. Men were more likely than women to have EBP (OR 3.5, 95% CI [2.12-5.56], p<0.001), a family history of diabetes (OR 3.6, 95% CI [2.1-5.9], p<0.001) and no formal education (OR 4.9, 95% CI [3.6-6.7], p<0.001).

Conclusions

Despite the relatively young mean age, significant percentages of workers were identified as having undiagnosed chronic health conditions, including EBP and elevated FBG, that require urgent medical attention and health education. The findings suggest that provision for annual health screening, either by mobile on-site clinics or by training the existing in-house paramedics, will help improve health of the factory workers.

Measurement and interpretation of hemoglobin concentration in clinical and field settings: a narrative review

Anemia affects over 800 million women and children globally. Defined as a limited or insufficient functional red blood cell supply in peripheral blood, anemia causes a reduced oxygen supply to tissues and can have serious health consequences for women and children. Hemoglobin (Hb) concentration is most commonly measured for anemia diagnosis. Methods to measure Hb are usually invasive (requiring a blood sample); however, advances in diagnostic and clinical chemistry over the past decade have led to the development of new noninvasive methods. Accurate diagnosis at the individual level is important to identify individuals who require treatment. At the population level, anemia prevalence estimates are often the impetus for national nutrition policies or programs. Thus, it is essential that methods for Hb measurement are sensitive, specific, accurate, and reproducible. The objective of our narrative review is to describe the basic principles, advantages, limitations, and quality control issues related to methods of Hb measurement in clinical and field settings. We also discuss other biomarkers and tests that can help to determine the severity and underlying causes of anemia. In conclusion, there are many established and emerging methods to measure Hb concentration, each with their own advantages, limitations, and factors to consider before use.

Community perceptions of paediatric severe anaemia in Uganda

Background

Severe anaemia remains a major cause of morbidity and mortality among children in sub-Saharan Africa. There is limited research on the beliefs and knowledge for paediatric severe anaemia in the region. The effect of these local beliefs and knowledge on the healthcare seeking of paediatric severe anaemia remains unknown.

Objective

To describe community perceptions of paediatric severe anaemia in Uganda.

Methods

Sixteen in-depth interviews of caregivers of children treated for severe anaemia and six focus group discussions of community members were conducted in three regions of Uganda between October and November 2017.

Results

There was no common local name used to describe paediatric severe anaemia, but the disease was understood in context as ‘having no blood’. Severe anaemia was identified to be a serious disease and the majority felt blood transfusion was the ideal treatment, but concomitant use of traditional and home remedies was also widespread. Participants articulated signs of severe pediatric anemia, such as palmar, conjunctival, and tongue pallor. Other signs described included jaundice, splenomegaly, difficulty in breathing and poor appetite. Poor feeding, malaria, splenomegaly and evil spirits were perceived to be the common causes of severe anaemia. Other causes included: human immunodeficiency virus (HIV), haemoglobinuria, fever, witchcraft, mosquito bites, and sickle cell. Splenomegaly and jaundice were perceived to be both signs and causes of severe anaemia. Severe anaemia was interpreted to be caused by evil spirits if it was either recurrent, led to sudden death, or manifested with cold extremities.

Conclusion

The community in Uganda perceived paediatric severe anaemia as a serious disease. Their understanding of the signs and perceived causes of severe anaemia to a large extent aligned with known clinical signs and biological causes. Belief in evil spirits persists and may be one obstacle to seeking timely medical care for paediatric severe anaemia.

Role of point of care Hb diagnostic devices in getting the right picture of anemia control: Tangi Rural Anemia Diagnostic Accuracy Study

Objectives: To study the accuracy and reliability of two point of care devices (Hemocue 201 [HC₂₀₁]) and Hemoglobin Colour Scale (HCS) with reference to automated laboratory analyser Sysmex XP 100 (Lab_SXP) and determine factors influencing their performances. To discuss certain design issues while ascertaining these parameters for its judicious use in both clinical context and disease burden studies.

Methods: Reliability and accuracy statistics were calculated for four population subgroups that were selected randomly using cluster sampling in a rural community of eastern India. Appropriate measures were taken to reduce biases in the study. Bland Altmann Plot was used to determine Bias and ROC curve analysis was used to suggest new cut-offs for HCS method.

Results: True prevalence varied across subgroups ranging from 12.56% in adolescent boys to 40.71% in adult women. Sensitivity for HC₂₀₁ was lowest among boys (80.39%) and highest among adult females (92.82%), while specificity was highest among adult males (86.94%) and lowest among adult females (75.00%). The variation across subgroups was due to differences in distribution of underlying Hb values. HC₂₀₁ has potential for use in clinical practice as well as disease burden estimation study. HCS was not suitable for use in clinical setting as the bias (−4.1 g/dl) was unacceptable. However, ROC analysis suggested certain cut-offs for different age groups and can be employed in poor resource settings for disease burden estimation study.

Conclusions: HC₂₀₁ is better than HCS as per the study. However, accuracy parameters are likely to vary depending on the distribution of underlying Hb distribution. Thus, same machines can demonstrate different accuracy parameters in different settings. There is need for designing studies that could help estimate these parameters each time on a subsample which would go a long way in efficiently using technology be it for guiding clinical decisions or public health actions.

A Kalman Filtering and Nonlinear Penalty Regression Approach for Noninvasive Anemia Detection with Palpebral Conjunctiva Images

Noninvasive medical procedures are usually preferable to their invasive counterparts in the medical community. Anemia examining through the palpebral conjunctiva is a convenient noninvasive procedure. The procedure can be automated to reduce the medical cost. We propose an anemia examining approach by using a Kalman filter (KF) and a regression method. The traditional KF is often used in time-dependent applications. Here, we modified the traditional KF for the time-independent data in medical applications. We simply compute the mean value of the red component of the palpebral conjunctiva image as our recognition feature and use a penalty regression algorithm to find a nonlinear curve that best fits the data of feature values and the corresponding levels of hemoglobin (Hb) concentration. To evaluate the proposed approach and several relevant approaches, we propose a risk evaluation scheme, where the entire Hb spectrum is divided into high-risk, low-risk, and doubtful intervals for anemia. The doubtful interval contains the Hb threshold, say 11 g/dL, separating anemia and nonanemia. A suspect sample is the sample falling in the doubtful interval. For the anemia screening purpose, we would like to have as less suspect samples as possible. The experimental results show that the modified KF reduces the number of suspect samples significantly for all the approaches considered here.

Examining palpebral conjunctiva for anemia assessment with image processing methods

Examining the hemoglobin level of blood is an important way to achieve the diagnosis of anemia, but it requires blood drawing and blood test. Examining the color distribution of palpebral conjunctiva is a standard procedure of anemia diagnosis, which requires no blood test. However, since color perception is not always consistent among different people, we attempt to imitate the way of physical examination of palpebral conjunctiva to detect anemia, so that computers can identify anemia patients automatically in a consolidated manner for a screening process. In this paper we propose two algorithms for anemia diagnosis. The first algorithm is intended to be simple and fast, while the second one to be more sophisticated and robust, providing an option for different applications. The first algorithm consists of a simple two-stage classifier. In the first stage, we use a thresholding decision technique based on a feature called high hue rate (HHR) (extracted from the HSI color space). In the second stage, a feature called pixel value in the middle (PVM) (extracted from the RGB color space) is proposed, followed by the use of a minimum distance classifier based on Mahalanobis distance. In the second algorithm, we consider 18 possible features, including a newly added entropy feature, some improved features from the first algorithm, and 13 features proposed in a previous work. We use correlation and simple statistics to select 3 relatively independent features (entropy, binarization of HHR, and PVM of G component) for classification using a support vector machine or an artificial neural network. Finally, we evaluate the classification performance of the proposed algorithms in terms of sensitivity, specificity, and Kappa value. The experimental results show relatively good performance and prove the feasibility of our attempt, which may encourage more follow-up study in the future.

Pediatric blood transfusion practices at a regional referral hospital in Kenya

BACKGROUND

Severe anemia in children is a major public health problem in sub-Saharan Africa. In this study we describe clinical and operational aspects of blood transfusion in children admitted to Coast Provincial General Hospital, Kenya.

STUDY DESIGN AND METHODS

This was an observational study where over a 2-year period, demographic and laboratory data were collected on all children for whom the hospital blood bank received a transfusion request. Clinical data were obtained by retrospective review of case notes over the first year.

RESULTS

There were 2789 requests for blood for children (median age, 1.8 years; interquartile range [IQR], 0.6-6.6 years); 70% (1950) of the samples were crossmatched with 85% (1663/1950) issued. Ninety percent (1505/1663) were presumed transfused. Median time from laboratory receipt of request to collection of blood was 3.6 hours (IQR, 1.4-12.8 hr). Case notes of 590 children were reviewed and median pretransfusion hemoglobin level was 6.0 g/dL (IQR, 4.2-9.1 g/dL). Ninety-four percent (186) were transfused "appropriately" while 52% (120) were transfused "inappropriately." There was significant disagreement between the clinical and laboratory diagnosis of severe anemia (exact McNemar's test; p < 0.0001). Antimalarials were prescribed for 65% (259) of children who received blood transfusions but only 41% (106) of these had a positive blood film.

CONCLUSION

In this setting, clinicians often order blood based on the clinical impression of "severe anemia." This has implications for laboratory workload and the blood supply itself. However, the majority of children with severe anemia were appropriately transfused. The use of antimalarials with blood transfusions irrespective of blood film results is common practice.

A question mark on iron deficiency in 185 million people of Pakistan: its outcomes and prevention

Micronutrient deficiency especially the iron deficiency is the bane of our lives, affecting all strata of society. Unfortunately, the women during pregnancy, adolescence, and children are under this curse particularly in developing countries like Pakistan. It is one of the biggest reasons of complications during pregnancy and malnourished children under five years of age. Maternal death, still-births, and underweight births are most common consequences of iron deficiency and these outbreaks as iron-deficiency anemia in Pakistan. Disastrous nature of iron deficiency requires an urgent call to eradicate it. Hence, the solution should not be frail comparing with the huge economic loss and other incompatibilities. Flour fortification, supplementation, dietary diversification, and especially maternal education are possible solutions for combating this micronutrient deficiency.

Anaemia in low-income and middle-income countries

Anaemia affects a quarter of the global population, including 293 million (47%) children younger than 5 years and 468 million (30%) non-pregnant women. In addition to anaemia's adverse health consequences, the economic effect of anaemia on human capital results in the loss of billions of dollars annually. In this paper, we review the epidemiology, clinical assessment, pathophysiology, and consequences of anaemia in low-income and middle-income countries. Our analysis shows that anaemia is disproportionately concentrated in low socioeconomic groups, and that maternal anaemia is strongly associated with child anaemia. Anaemia has multifactorial causes involving complex interaction between nutrition, infectious diseases, and other factors, and this complexity presents a challenge to effectively address the population determinants of anaemia. Reduction of knowledge gaps in research and policy and improvement of the implementation of effective population-level strategies will help to alleviate the anaemia burden in low-resource settings.

Accelerating improvements in nutritional and health status of young children in the Sahel region of Sub-Saharan Africa: review of international guidelines on infant and young child feeding and nutrition

The United Nations Convention on the Rights of the Child holds governments responsible to ensure children's right to the highest attainable standard of health by providing breastfeeding support, and access to nutritious foods, appropriate health care, and clean drinking water. International experts have identified key child care practices and programmatic activities that are proven to be effective at reducing infant and young child undernutrition, morbidity, and mortality. Nevertheless, progress towards reducing the prevalence of undernutrition has been sporadic across countries of the Sahel sub-region of Sub-Saharan Africa. In view of this uneven progress, a working group of international agencies was convened to 'Reposition children's right to adequate nutrition in the Sahel.' The first step towards this goal was to organize a situational analysis of the legislative, research, and programmatic activities related to infant and young child nutrition (IYCN) in six countries of the sub-region: Burkina Faso, Chad, Mali, Mauritania, Niger, and Senegal. The purposes of this introductory paper are to review current information concerning the nutritional and health status of infants and young children in the Sahel and to summarize international guidelines on optimal IYCN practices. These guidelines were used in completing the above-mentioned situational analyses and encompass specific recommendations on: (i) breastfeeding (introduction within the first hour after birth, exclusivity to 6 months, continuation to at least 24 months); (ii) complementary feeding (introduction at 6 months, use of nutrient dense foods, adequate frequency and consistency, and responsive feeding); (iii) prevention and/or treatment of micronutrient deficiencies (vitamin A, zinc, iron and anaemia, and iodine); (iv) prevention and/or treatment of acute malnutrition; (v) feeding practices adapted to the maternal situation to reduce mother-to-child transmission of HIV; (vi) activities to ensure food security; and (vii) the promotion of hygienic practices concerning food preparation and storage and environmental sanitation. The following papers in this issue will present results of the situational analyses for the individual countries.

Accuracy and reliability of pallor for detecting anaemia: a hospital-based diagnostic accuracy study

Background

Anaemia is a common disorder. Most health providers in resource poor settings rely on physical signs to diagnose anaemia. We aimed to determine the diagnostic accuracy of pallor for anaemia by using haemoglobin as the reference standard.

Methodology/Principal Findings

In May 2007, we enrolled consecutive patients over 12 years of age, able to consent and willing to participate and who had a haemoglobin measurement taken within a day of assessment of clinical pallor from outpatient and medicine inpatient department of a teaching hospital. We did a blind and independent comparison of physical signs (examination of conjunctivae, tongue, palms and nailbed for pallor) and the reference standard (haemoglobin estimation by an electronic cell counter). Diagnostic accuracy was measured by calculating likelihood ratio values and 95% confidence intervals (CI) at different haemoglobin thresholds and area under the receiver operating characteristic curve. Two observers examined a subset of patients (n = 128) to determine the inter-observer agreement, calculated by kappa statistics. We studied 390 patients (mean age 40.1 [SD 17.08] years); of whom 48% were women. The haemoglobin was <7 g/dL in 8% (95% confidence interval, 5, 10) patients; <9 g/dL in 21% (17, 26) patients and <12 g/dL in 64% (60, 70) patients. Among patients with haemoglobin <7 g/dL, presence of severe tongue pallor yielded a LR of 9.87 (2.81, 34.6) and its absence yielded a LR of 0. The tongue pallor outperformed other pallor sites and was also the best discriminator of anaemia at haemoglobin thresholds of 7 g/dL and 9 g/dL (area under the receiver operating characteristic curves (ROC area  = 0.84 [0.77, 0.90] and 0.71[0.64, 0.76]) respectively. The agreement between the two observers for detection of anaemia was poor (kappa values  = 0.07 for conjunctival pallor and 0.20 for tongue pallor).

Conclusions/Significance

Clinical assessment of pallor can rule out and modestly rule in severe anaemia.

Thrombocytopenia and anemia in infants and children

Thrombocytopenia and anemia are the two most common hematologic conditions seen in the pediatric emergency department. Providers of emergency pediatric care must have an understanding of the causes and therapies for the various conditions that result from thrombocytopenia and anemia. This article reviews the common causes of isolated thrombocytopenia and anemia in infancy and childhood.

Validity of using pallor to detect children with mild anemia

BACKGROUND

The World Health Organization recommends the assessment of pallor as an indicator for the presence of anemia in children under 5 years of age at a primary care level where anemia is prevalent. The aim of the present study was to study the validity and interobserver agreement of pallor examination in recognition of anemia in children under 2 years of age.

METHODS

Healthy children aged 6-24 months (n = 141) admitted to well baby clinic were assessed for the presence of pallor at three anatomic sites (palm, conjunctiva, buccal mucosa) on admission by two blinded observers (Integrated Management of Childhood Illness [IMCI] certificate pediatrician and a pediatric resident). Clinical examination for pallor was made without having the information on the child's hemoglobin level or of the other observer's assessment for pallor. Anemia was defined as hemoglobin level <11 g/dL. The exclusion criteria included the presence of any acute or chronic illness on admission, and treatment for anemia within the 3 months preceding the study.

RESULTS

The mean age of the children was 8.0 +/- 2.7 months; 71 (50%) were boys. Blood samples indicated anemia in 33 children (23%). Palmar pallor alone significantly had highest sensitivity (sensitivity 72% and specificity 75%, positive predictive value 48%) to detect anemia for the IMCI-trained pediatrician. The interobserver agreement was highest for buccal and conjunctival pallor (kappa = 0.64 and 0.63, respectively), and lowest for palmar pallor (kappa = 0.49).

CONCLUSION

Palmar pallor is a sensitive and specific sign of mild anemia when used by the IMCI-trained pediatrician.

Ability of mothers to diagnose fever and anaemia in their young children, in a malaria-endemic region of West Africa

The rapid and correct diagnosis of fever and anaemia at the household level is a prerequisite for the successful management and control of life-threatening disease among young children, particularly in malaria-endemic areas of Africa. The ability of mothers to diagnose fever and anaemia in their young children has recently been explored, as part of a large, birth-cohort study in rural, north-western Burkina Faso. During a cross-sectional survey in six villages, 345 children aged, <3 years and their mothers were investigated. Each mother was asked if she considered her child to be febrile and/or anaemic before that child's temperature and haematocrit were measured, with an electronic thermometer and portable centrifuge, respectively. The recorded prevalences of fever (> or =37.5 degrees C) and anaemia (haematocrit, <25%) in the children were 12.2% and 21.4%, respectively. The mothers' diagnoses had a sensitivity of 76.2% [95% confidence interval (CI)=60.6%-88.0%] for fever and 4.1% (CI=0.8%-11.4%) for anaemia, with corresponding specificities of 87.1% (CI=82.8%-90.7%) and 95.9% (CI=92.9%-98.0%). Mothers in rural Africa appear to be fairly accurate in detecting fever in their children but less accurate in detecting anaemia. While malaria control needs to employ a mix of preventive and curative measures, anaemia control will benefit from community-based malaria-control measures as well as broader approaches addressing the nutritional status of young children.

Non-invasive determination of hemoglobin by digital photography of palpebral conjunctiva

The objective of this study was to determine whether digital photography could be used to calculate hemoglobin. This prospective blinded study was conducted in a tertiary care Emergency Department (ED). A convenience sample of 65 patients provided consent; 44 patients were enrolled for formula derivation and 19 for prospective analysis. Hemoglobin concentration in blood was determined by a cell counter. Software was developed to predict the hemoglobin value based on a formula derived using the images and known hemoglobin values from a derivation set of patients. Pearson's rank order correlation between the calculated and measured hemoglobin was r(77) = 0.634, p < 0.01 for the derivation group and r(36) = 0.522, p < 0.01 for the evaluation group. It is possible to derive an objective method that correlates conjunctiva color with measured hemoglobin and, when applied prospectively, is able to predict hemoglobin concentration in ED patients. This technology has broad applications in regions with limited resources.

Anaemia, iron status and vitamin A deficiency among adolescent refugees in Kenya and Nepal

Objective

To investigate the prevalence of anaemia (haemoglobin < 11.0 to 13.0 g dl−1depending on age and sex group), iron deficiency (transferrin receptor concentration > 8.3 μg ml−1) and vitamin A deficiency (serum retinol < 0.7 μmoll−1) in adolescent refugees.

Design

Cross-sectional surveys.

Setting

Kakuma refugee camp in Kenya and seven refugee camps in Nepal.

Subjects

Adolescent refugee residents in these camps.

Results

Anaemia was present in 46% (95% confidence interval (CI): 42–51) of adolescents in Kenya and in 24% (95% CI: 20–28) of adolescents in Nepal. The sensitivity of palmar pallor in detecting anaemia was 21%. In addition, 43% (95% CI: 36–50) and 53% (95% CI: 46–61) of adolescents in Kenya and Nepal, respectively, had iron deficiency. In both surveys, anaemia occurred more commonly among adolescents with iron deficiency. Vitamin A deficiency was found in 15% (95% CI: 10–20) of adolescents in Kenya and 30% (95% CI: 24–37) of adolescents in Nepal. Night blindness was not more common in adolescents with vitamin A deficiency than in those without vitamin A deficiency. In Kenya, one of the seven adolescents with Bitot's spots had vitamin A deficiency.

Conclusions

Anaemia, iron deficiency and vitamin A deficiency are common among adolescents in refugee populations. Such adolescents need to increase intakes of these nutrients; however, the lack of routine access makes programmes targeting adolescents difficult. Adolescent refugees should be considered for assessment along with other at-risk groups in displaced populations.

Algorithm for the diagnosis of anaemia without laboratory facilities among small children in a malaria endemic area of rural Tanzania

BACKGROUND

Anaemia among small children in tropical Africa is common and often caused by infection with Plasmodium falciparum. The diagnosis of anaemia is difficult without a laboratory estimation of haemoglobin. The aim of this study was to examine if clinical findings related to malaria and anaemia would help to detect moderate and/or severe anaemia in children in rural Tanzania.

METHODS

Children between 6 and 36 months were examined by health workers in an Out Patient Department (OPD) to detect severe anaemia (packed cell volume, PCV< or =20%) and in a cross sectional survey at village level to identify moderate anaemia (PCV 21-25%). History of recent fever and treatments was recorded and a clinical examination was performed.

FINDINGS

In the survey, comparison of 65 moderately anaemic children with 373 mild/non anaemic children revealed no differences in history of fever or in the clinical examination. In the OPD comparison of 100 severely anaemic children with 116 non-severely anaemic control children revealed that pallor, respiratory rate, number of fever days last week, deteriorated general condition, heart rate, age, splenomegaly, low body weight and elevated body temperature were all indicators of severe 'anaemia, only pallor, respiratory rate, fever days and palpable spleen however, remained associated with severe anaemia in multiple regression analysis. The combination of any pallor and either respiratory rate >55/min or fever >3 days, could predict severe anaemia with a sensitivity of 96% and a specificity of 71%. This was better than the currently recommended signs of severe pallor or an approximation of the Integrated Management of Childhood Illness (IMCI) criteria's for referral of children.

INTERPRETATION

At primary health care level detection of severe anaemia can be improved by information about fever duration and determination of respiratory rate in children with pallor.

Pallor as a sign of anaemia in small Tanzanian children at different health care levels

BACKGROUND

Anaemia is a major complication of Plasmodium falciparum malaria among small children in sub-Saharan Africa. We studied the performance of the Integrated Management of Childhood Illness (IMCI) recommended assessment of no/some/severe pallor as predictor of anaemia in health surveys at community level and in clinical practice in an out patient department (OPD) and in a hospital ward in rural Tanzania.

METHODS

The study was undertaken among 6-36 months old children. Pallor was evaluated as a combined assessment of conjunctiva, tongue and palms and categorised as no, some or severe pallor. Packed cell volume (PCV) was measured and related to pallor.

FINDINGS

A total of 740 examinations were performed at village, OPD and in the hospital ward. The prevalences of severe pallor were 0%, 1.5% and 7% respectively. The prevalences of any pallor were 14%, 41% and 86%. The prevalences of severe anaemia (PCV<21%) were 1%, 5% and 81% and of any anaemia (PCV<33%) 68%, 73% and 98%. Severe pallor could not detect severe anaemia. The sensitivities were only 0%, 0% and 8%. The sensitivities of any pallor to detect severe anaemia were however 86% and 98% for children at the health care facility level, but still of relatively poor predictive values since the specificities were only 61% and 68%.

INTERPRETATION

Division of pallor into some or severe degrees was of no use at any health care level. The identification of any pallor was of no use at village level, but it may possibly be of some value as a screening test for severe anaemia at health care facilities, if additional assessment is included in view of the low specificity and positive predictive value of the finding.

Diffuse reflectance spectra of the palpebral conjunctiva and its utility as a noninvasive indicator of total hemoglobin

The palpebral conjunctiva is an attractive location to qualitatively examine for the presence of anemia; however, this method of diagnosis has not been shown to be accurate. A spectroscopic examination of the palpebral conjunctiva enables the use of a quantitative parameter as a basis for diagnoses. Visible range diffuse reflectance spectra from the palpebral conjunctiva are examined from 30 patients and hemoglobin levels are extracted from these signatures using both a partial least-squares (PLS) multivariate regression model and a discrete spectral region model. Hemoglobin concentration derived from both these models is compared to an in vitro measurement of hemoglobin. Root mean squared errors of cross validation for the two analytical methods are 0.67 g/dL and 1.07 g/dL, respectively. Conjunctival reflectance spectra coupled with a PLS analysis achieve an enhanced specificity and sensitivity for anemia diagnoses over reported observational studies using the palpebral conjunctiva and achieve improved accuracy to other reported methods of noninvasive hemoglobin measurement.

Accuracy of clinical pallor in the diagnosis of anaemia in children: a meta-analysis

BACKGROUND

Anaemia is highly prevalent in children of developing countries. It is associated with impaired physical growth and mental development. Palmar pallor is recommended at primary level for diagnosing it, on the basis of few studies. The objective of the study was to systematically assess the accuracy of clinical signs in the diagnosis of anaemia in children.

METHODS

A systematic review on the accuracy of clinical signs of anaemia in children. We performed an Internet search in various databases and an additional reference tracking. Studies had to be on performance of clinical signs in the diagnosis of anaemia, using haemoglobin as the gold standard. We calculated pooled diagnostic likelihood ratios (LR's) and odds ratios (DOR's) for each clinical sign at different haemoglobin thresholds.

RESULTS

Eleven articles met the inclusion criteria. Most studies were performed in Africa, in children underfive. Chi-square test for proportions and Cochran Q for DOR's and for LR's showed heterogeneity. Type of observer and haemoglobin technique influenced the results. Pooling was done using the random effects model. Pooled DOR at haemoglobin <11 g/dL was 4.3 (95% CI 2.6-7.2) for palmar pallor, 3.7 (2.3-5.9) for conjunctival pallor, and 3.4 (1.8-6.3) for nailbed pallor. DOR's and LR's were slightly better for nailbed pallor at all other haemoglobin thresholds. The accuracy did not vary substantially after excluding outliers.

CONCLUSION

This meta-analysis did not document a highly accurate clinical sign of anaemia. In view of poor performance of clinical signs, universal iron supplementation may be an adequate control strategy in high prevalence areas. Further well-designed studies are needed in settings other than Africa. They should assess inter-observer variation, performance of combined clinical signs, phenotypic differences, and different degrees of anaemia.

Validação e reprodutibilidade de sinais clínicos no diagnóstico de anemia em crianças

Este trabalho teve como objetivo avaliar a validade e reprodutibilidade dos sinais clínicos (palidez palmar e conjuntival) no diagnóstico de anemia em crianças de 6-23 meses, no Nordeste do Brasil, por meio de estudo transversal com amostra de 421 crianças, realizado nos ambulatórios de pediatria e puericultura do Instituto Materno Infantil de Pernambuco. Os sinais clínicos foram avaliados por dois examinadores. A reprodutibilidade foi avaliada pelo coeficiente de kappa e a validação (sensibilidade e especificidade) foi realizada utilizando-se a hemoglobina como padrão. Os sinais clínicos demonstraram baixa reprodutibilidade (kappa de 0,24-0,25). A maior sensibilidade para diagnosticar anemia (Hb < 11g/dl) e anemia moderada/ grave (Hb < 9g/dl), respectivamente, foi apresentada pela combinação de palidez palmar ou conjuntival (39,7% e 53,5%), seguida pela palidez palmar isoladamente (29,9% e 40,0%). A maior especificidade foi para a palidez palmar comparada à palma da mão da mãe (95,5% e 90,1% para Hb < 11g/dl e Hb < 9g/dl, respectivamente). A sensibilidade dos sinais clínicos foi melhor para diagnosticar a anemia moderada/grave, especialmente quando a palidez palmar e conjuntival são combinadas, sugerindo que a utilização dos mesmos não se constitui em um bom instrumento para diagnosticar anemia leve.

Valeur diagnostique de la pâleur des téguments dans l'anémie chez les femmes enceintes au Bénin

Anemia in pregnant women is a common and severe public health problem encountered in developing countries. Its detection is most often based upon clinical examination and observation of conjunctive pallor; however, little is known or documented on the performance indicators of this clinical method in Africa. This work aims assess the value of performance indicators in detecting moderate and severe anemia by means of tegument pallor examination in a maternity ward in rural Benin. To this end, 480 pregnant women were recruited at random during their prenatal visits to a rural maternity clinic. Two independent observers had noted conjunctive or other forms of teguments in all of the women selected, and a concentration of hemoglobin was confirmed by a blood test. An analysis of the results indicated that 67.4% of pregnant women were biologically anemic (Hb < 11.0 g/dl) while only 49% among them were clinically anemic. The sensitivity of the clinical observation method for conjunctive pallor is 87.5% for severe anemia and 74% for moderate anemia. Its positive predictive value is 62.5% for moderate anemia and very weak for light cases of anemia, at only 3%. The accuracy of this clinical method varies from 51-71%, when the likelihood is determined as 1.8 to 2.3. Its reproducibility appears equally weak and clinical observer variability seems to be poor to fair agreement at k = 0.34 (p = 0.00). For practical reasons, the authors suggest the strengthening of the teaching of this method to obstetrics' care providers and medical students in training in order to improve its more effective use and practice in rural maternity units without laboratories.

Recognition of pallor associated with severe anaemia by primary caregivers in western Kenya

OBJECTIVES

To explore which pallor signs and symptoms of severe anaemia could be recognized by primary caregivers following minimal instructions.

METHODS

Data from three community-based cross-sectional surveys were used. Test characteristics to predict haemoglobin (Hb) concentrations < 5 and < 7 g/dl were compared for different combinations of pallor signs (eyelid, tongue, palmar and nailbed) and symptoms.

RESULTS

Pallor signs and haemoglobin levels were available for 3782 children under 5 years of age from 2609 households. Comparisons of the sensitivity and specificity at a range of haemoglobin cut-offs showed that Hb < 5 g/dl was associated with the greatest combined sensitivity and specificity for pallor at any anatomical site (sensitivity = 75.6%, specificity = 63.0%, Youden index = 38.6). Higher or lower haemoglobin cut-offs resulted in more children being misclassified. Similar results were obtained for all individual pallor sites. Combining a history of soil eating with pallor at any site improved the sensitivity (87.8%) to detect Hb < 5 g/dl with a smaller reduction in specificity (53.3%; Youden index 41.1). Other combinations including respiratory signs or poor feeding resulted in lower accuracy.

CONCLUSION

Primary caregivers can recognize severe anaemia (Hb < 5 g/dl) in their children, but only with moderate accuracy. Soil eating should be considered as an additional indicator of severe anaemia. The effect of training caretakers to improve recognition of severe anaemia and care-seeking behaviour at the household level should be assessed in prospective community-based studies.

Taking a medical history and using a colour scale during clinical examination of pallor improves detection of anaemia

We developed a colour tint scale to use as an aid in the clinical assessment of anaemia by measuring conjunctival pallor. The objectives of this study were to evaluate the accuracy and agreement among observers in detecting anaemia in three sequential phases with incremental information using clinical pallor of different anatomical sites, subsequently adding subjects' medical history for physical symptoms and the colour scale. After training in the application of these three sequential assessments, 12 primary health workers were assigned to independently examine 198 anaemic and 254 non-anaemic pregnant women while blind to the true anaemic status. Their assessments in each phase were then compared with the anaemic status based on haemoglobin level, measured using HemoCue, taken as the gold standard, to determine sensitivity and specificity, and agreements among observers in detecting anaemia were calculated. In the three sequential phases of assessment the sensitivities were 73.8, 78.3, 82.9% and specificities 76.0, 84.7 and 90.9%, respectively. In each subsequent step, the improvements in both the sensitivity and specificity were statistically significant [P(chi2(McNemar)) < 0.01]. Kappa statistics for agreement among 12 observers for assessing anaemia in the sequential phases were 0.50, 0.71 and 0.82, respectively. The Spearman rank correlation coefficient between haemoglobin level and the colour scale reading was 0.68 (P < 0.001). Taking medical history and incorporating a simple colour tint scale with examination of pallor improved the sensitivity, specificity and agreement for detection of anaemia by health workers.

How effective is antenatal care in preventing maternal mortality and serious morbidity? An overview of the evidence

This is an overview of evidence of the effectiveness of antenatal care in relation to maternal mortality and serious morbidity, focused in particular on developing countries. It concentrates on the major causes of maternal mortality, and traces their antecedent morbidities and risk factors in pregnancy. It also includes interventions aimed at preventing, detecting or treating any stage along this pathway during pregnancy. This is an updated and expanded version of a review first published by the World Health Organization (WHO) in 1992. The scientific evidence from randomised controlled trials and other types of intervention or observational study on the effectiveness of these interventions is reviewed critically. The sources and quality of available data, and possible biases in their collection or interpretation are considered. As in other areas of maternal health, good-quality evidence is scarce and, just as in many aspects of health care generally, there are interventions in current practice that have not been subjected to rigorous evaluation. A table of antenatal interventions of proven effectiveness in conditions that can lead to maternal mortality or serious morbidity is presented. Interventions for which there is some promising evidence, short of proof, of effectiveness are explored, and the outstanding questions formulated. These are presented in a series of tables with suggestions about the types of study needed to answer them.

Field trial of a haemoglobin colour scale: an effective tool to detect anaemia in preschool children

The objective of this study was to evaluate the performance of the Haemoglobin Colour Scale, developed by Stott and Lewis, to diagnose anaemia in a primary health care setting where anaemia was prevalent and severe. Three measures of anaemia were compared in 535 preschool children: haemoglobin based on the Haemoglobin Colour Scale, clinical assessment in three sites (conjunctiva, palm and nail bed) and haemoglobin based on a digital haemoglobinometer (HemoCue method) taken as gold standard. A statistically significant correlation (r = 0.80, coefficient = 0.77 and Y intercept = 2.33) was obtained between the results of the Haemoglobin Colour Scale and the HemoCue. In more than 80% of cases, the difference between the colour scale readings and the results of the HemoCue was within 1 g/dl. Of 415 anaemic children (Hb < 11 g/dl by HemoCue), 85.2% were so identified by the Haemoglobin Colour Scale and 19.7% were classified anaemic by clinical pallor. Of 19 severely anaemic children (Hb < 7 g/dl by HemoCue), 73.6% were identified as severely anaemic and 100% were classified as anaemic by the colour scale, 61.1% were classified as anaemic using clinical pallor. We found the Haemoglobin Colour Scale to be a useful tool in identifying anaemic and severely anaemic children. Efficiencies in term of cost, accuracy and time make it an important resource in primary health care settings in developing countries. Further testing with other staff in other settings is recommended to determine the usefulness of large-scale distribution.