Haemoglobin colour scale for anaemia diagnosis where there is no laboratory: a systematic review

Feasibility of smartphone colorimetry of the face as an anaemia screening tool for infants and young children in Ghana

BACKGROUND

Anaemia affects approximately a quarter of the global population. When anaemia occurs during childhood, it can increase susceptibility to infectious diseases and impair cognitive development. This research uses smartphone-based colorimetry to develop a non-invasive technique for screening for anaemia in a previously understudied population of infants and young children in Ghana.

METHODS

We propose a colorimetric algorithm for screening for anaemia which uses a novel combination of three regions of interest: the lower eyelid (palpebral conjunctiva), the sclera, and the mucosal membrane adjacent to the lower lip. These regions are chosen to have minimal skin pigmentation occluding the blood chromaticity. As part of the algorithm development, different methods were compared for (1) accounting for varying ambient lighting, and (2) choosing a chromaticity metric for each region of interest. In comparison to some prior work, no specialist hardware (such as a colour reference card) is required for image acquisition.

RESULTS

Sixty-two patients under 4 years of age were recruited as a convenience clinical sample in Korle Bu Teaching Hospital, Ghana. Forty-three of these had quality images for all regions of interest. Using a naïve Bayes classifier, this method was capable of screening for anaemia (<11.0g/dL haemoglobin concentration) vs healthy blood haemoglobin concentration (≥11.0g/dL) with a sensitivity of 92.9% (95% CI 66.1% to 99.8%), a specificity of 89.7% (72.7% to 97.8%) when acting on unseen data, using only an affordable smartphone and no additional hardware.

CONCLUSION

These results add to the body of evidence suggesting that smartphone colorimetry is likely to be a useful tool for making anaemia screening more widely available. However, there remains no consensus on the optimal method for image preprocessing or feature extraction, especially across diverse patient populations.

A Low-Cost Test for Anemia Using an Artificial Neural Network

BACKGROUND

Anemia during pregnancy can complicate maternal and neonatal health and even lead to fatal consequences if not diagnosed early on. Around 99% of women who face maternal mortality are from middle or low-income countries. Early screening of anemia could facilitate improved health outcomes in pregnant women. Point of care techniques are preferred due to their ability to provide results rapidly and because they can be used by personnel with minimal or no training. Such techniques are especially useful in resource-constrained settings like rural parts of developing countries.

OBJECTIVES

The aim of the study was to develop a tool using an Artificial Neural Network (ANN) to estimate hemoglobin values using color information recorded from blood sample images. Our method utilizes inexpensive consumables and a simple image acquisition setup that can be assembled easily.

METHODS

This study explores a neural network model to estimate the hemoglobin content in an individual's blood sample. Blood samples were collected from 86 volunteers and the images of blood drops were obtained using an image acquisition setup designed by the team. The color intensity values calculated from the blood drop images were used as feature descriptors for the samples. The features obtained from our samples were consequently fed to the Artificial Neural Network.

RESULTS

Our neural network that gives the best result has the architecture of 11 neurons in each of the 5 layers. The best model gave estimated hemoglobin levels by analyzing color of blood samples with an accuracy of ±1.8 g/dl Limits of agreement (LOA) and bias 0.03 g/dl (with mean error of 0.75 g/dl). The model was subsequently tested with a validation set prepared from an additional 65 samples. The estimated hemoglobin levels gave an accuracy of +2 g/dl to -1.9 g/dl Limits of agreement (LOA) and bias 0.06 g/dl (with mean error of 0.78 g/dl).

CONCLUSION

Optimization of sensitivity and specificity has been able to achieve the sensitivity and specificity values as 95.5% and 52% respectively. These results are at par with the contemporary measurement techniques indicating that our method can be used as a workable screening technique itself.

Improving access to maternal health services among rural hard-to-reach fishing communities in Uganda, the role of community health workers

OBJECTIVES

To explore whether community health worker household-based maternal health visits improve antenatal care and skilled birth attendance among hard-to-reach fishing villages on Lake Victoria, Uganda.

METHODS

This quasi-experimental 18-month prospective study involved 486 consenting women aged 15-49 years, who were pregnant or had a pregnancy outcome in the past 6 months, from 6 island fishing communities. The community health worker household-based intervention (community health workers' household visits to provide counseling, blood pressure measurement, anemia, and HIV testing) involved 243 women from three fishing communities. Random effects logistic regression was used to determine the association between the community health worker intervention and antenatal care and skilled birth attendance among women who had at least 5 months of pregnancy or childbirth at follow-up.

RESULTS

Almost all women accepted the community health worker intervention (90.9% (221/243)). Hypertension was at 12.5% (27/216) among those who accepted blood pressure measurements, a third (33.3% (9/27)) were pregnant. HIV prevalence was 23.5% (52/221). Over a third (34.2% (69/202)) of women tested had anemia (hemoglobin levels less than 11 g/dL). The community health worker intervention was associated with attendance of first antenatal care visit within 20 weeks of pregnancy (adjusted odd ratio = 2.1 (95% confidence interval 0.6-7.6)), attendance of at least four antenatal care visits (adjusted odd ratio = 0.9 (95% confidence interval 0.4-2.0)), and skilled birth attendance (adjusted odd ratio = 0.5 (95% confidence interval 0.1-1.5)), though not statistically significant.

CONCLUSION

Community health workers have a crucial role in improving early antenatal care attendance, early community-based diagnosis of anemia, hypertensive disorders, and HIV among women in these hard-to-reach fishing communities.

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.

Smartphone-Enabled Paper-Based Hemoglobin Sensor for Extreme Point-of-Care Diagnostics

We report a simple, affordable (∼0.02 US $/test), rapid (within 5 min), and quantitative paper-based sensor integrated with smartphone application for on-spot detection of hemoglobin (Hgb) concentration using approximately 10 μL of finger-pricked blood. Quantitative analytical colorimetry is achieved via an Android-based application (Sens-Hb), integrating key operational steps of image acquisition, real-time analysis, and result dissemination. Further, feedback from the machine learning algorithm for adaptation of calibration data offers consistent dynamic improvement for precise predictions of the test results. Our study reveals a successful deployment of the extreme point-of-care test in rural settings where no infrastructural facilities for diagnostics are available. The Hgb test device is validated both in the controlled laboratory environment (n = 200) and on the field experiments (n = 142) executed in four different Indian villages. Validation results are well correlated with the pathological gold standard results (r = 0.9583) with high sensitivity and specificity for the healthy (n = 136) (>11 g/dL) (specificity: 97.2%), mildly anemic (n = 55) (<11 g/dL) (sensitivity: 87.5%, specificity: 100%), and severely anemic (n = 9) (<7 g/dL) (sensitivity: 100%, specificity: 100%) samples. Results from field trials reveal that only below 5% cases of the results are interpreted erroneously by classifying mildly anemic patients as healthy ones. On-field deployment has unveiled the test kit to be extremely user friendly that can be handled by minimally trained frontline workers for catering the needs of the underserved communities.

Novel Biased Normalized Cuts Approach for the Automatic Segmentation of the Conjunctiva

Anemia is a common public health disease diffused worldwide. In many cases it affects the daily lives of patients needing medical assistance and continuous monitoring. Medical literature states empirical evidence of a correlation between conjunctival pallor on physical examinations and its association with anemia diagnosis. Although humans exhibit a natural expertise in pattern recognition and associative skills based on hue properties, the variance of estimates is high, requiring blood sampling even for monitoring. To design automatic systems for the objective evaluation of pallor utilizing digital images of the conjunctiva, it is necessary to obtain reliable automatic segmentation of the eyelid conjunctiva. In this study, we propose a graph partitioning segmentation approach. The semantic segmentation procedure of a diagnostically meaningful region of interest has been proposed for exploiting normalized cuts for perceptual grouping, thereby introducing a bias towards spectrophotometry features of hemoglobin. The reliability of the identification of the region of interest is demonstrated both with standard metrics and by measuring the correlation between the color of the ROI and the hemoglobin level based on 94 samples distributed in relation to age, sex and hemoglobin concentration. The region of interest automatically segmented is suitable for diagnostic procedures based on quantitative hemoglobin estimation of exposed tissues of the conjunctiva.

Improving the effectiveness of point of care tests for malaria and anaemia: a qualitative study across three Ghanaian antenatal clinics

Background

Anaemia and malaria are both major contributors to maternal and child mortality, and morbidity, with some of the worst outcomes occurring in sub-Saharan Africa. Point of care tests (POCT), if used appropriately, provide a simple, inexpensive form of diagnostic testing, as a reliable alternative when laboratory tests are not readily available. In such resource limited settings, clinical staff tend to rely on symptom-based diagnosis and presumptive treatment. This study uses qualitative methods to identify the current practice of POCT use for malaria and anaemia, to explore the enablers and barriers to effective implementation of these POCT, and to determine how relationships between each of the stakeholder groups may impact on POCT use.

Methods

Staff (clinical and laboratory) and patients (pregnant women) at three antenatal care facilities within the Ashanti Region of Ghana participated in interviews and focus group discussions (FGDs). An initial coding framework was developed based on the pre-defined objectives of the study. Thematic analysis was used to identify subthemes and categories within each of the key themes.

Results

At the time data were collected all three facilities used malaria POCT either as an adjunct to microscopy, or as their only form of malaria testing. Although all three facilities were familiar with haemoglobin colour scale (HCS), none of the facilities used them routinely. Clinical staff perceived symptom-based diagnosis was a quick way to diagnosis because access to POCT during consultations was unreliable, but recognized disadvantages associated with symptom-based diagnosis.

Perceived advantages of malaria and anaemia POCT were user-friendliness, improved diagnosis and opportunity for patient engagement, as well as lower cost implication for patients. Perceived disadvantages included likelihood of missed diagnosis of mild anaemia, as well as likelihood of human error leading to in accurate diagnosis which could impact on patient trust. Poor communication and lack of trust between staff groups was also identified as a barrier to effective uptake of POCT.

Conclusions

Consistent supply of POCT as well as staff training and staff and patient engagement, are fundamental to successful uptake of POCT for effective malaria and anaemia management.

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.

Evaluation of the diagnostic accuracy and cost of different methods for the assessment of severe anaemia in hospitalised children in Eastern Uganda

Background: Severe anaemia in children requiring hospital admission is a major public health problem in malaria-endemic Africa. Affordable methods for the assessment of haemoglobin have not been validated against gold standard measures for identifying those with severe anaemia requiring a blood transfusion, despite this resource being in short supply. Methods: We conducted a prospective descriptive study of hospitalized children aged 2 months - 12 years at Mbale and Soroti Regional Referral Hospitals, assessed to have pallor at triage by a nurse and two clinicians. Haemoglobin levels were measured using the HemoCue ® Hb 301 system (gold standard); the Haemoglobin Colour Scale; Colorimetric and Sahli's methods. We report clinical assessments of the degree of pallor, clinicians' intention to transfuse, inter-observer agreement, limits of agreement using the Bland-Altman method, and the sensitivity and specificity of each method in comparison to HemoCue ® Results: We recruited 322 children, clinically-assessed by the admitting nurse (n=314) as having severe (166; 51.6%), moderate (97; 30.1%) or mild (51; 15.8%) pallor. Agreement between the clinicians and the nurse were good: Clinician A Kappa=0.68 (0.60-0.76) and Clinician B Kappa=0.62 (0.53-0.71) respectively ( P<0.0001 for both). The nurse, clinicians A and B indicated that of 94/116 (81.0%), 83/121 (68.6%) and 93/120 (77.5%) respectively required transfusion. HemoCue ® readings indicated anaemia as mild (Hb10.0-11.9g/dl) in 8/292 (2.7%), moderate (Hb5.0-9.9g/dl) in 132/292 (45.2%) and severe (Hb<5.0g/dl) in 152/292 (52.1%). Comparing to HemoCue® the Sahli's method performed best in estimation of severe anaemia, with sensitivity 84.0% and specificity 87.9% and a Kappa score of  0.70 (0.64-0.80). Conclusions: Clinical assessment of severe pallor results has a low specificity for the diagnosis of severe anaemia. To target blood transfusion Hb measurement by either Hemocue® or Sahli's method for the cost of USD 4 or and USD 0.25 per test, respectively would be more cost-effective.

Evaluation of the diagnostic accuracy and cost of different methods for the assessment of severe anaemia in hospitalised children in Eastern Uganda

Background: Severe anaemia in children requiring hospital admission is a major public health problem in malaria-endemic Africa. Affordable methods for the assessment of haemoglobin have not been validated against gold standard measures for identifying those with severe anaemia requiring a blood transfusion, despite this resource being in short supply. Methods: We conducted a prospective descriptive study of hospitalized children aged 2 months - 12 years at Mbale and Soroti Regional Referral Hospitals, assessed to have pallor at triage by a nurse and two clinicians. Haemoglobin levels were measured using the HemoCue ® Hb 301 system (gold standard); the Haemoglobin Colour Scale; calorimetric and Sahli's methods. We report clinical assessments of the degree of pallor, clinicians' intention to transfuse, inter-observer agreement, limits of agreement using the Bland-Altman method, and the sensitivity and specificity of each method in comparison to HemoCue ® Results: We recruited 322 children assessed by the admitting nurse as having severe (164; 51.0%), moderate (99; 30.7%) or mild (57; 17.7%) pallor. Agreement between the clinicians and the nurse were good: Clinician A Kappa=0.68 (0.60-0.76) and Clinician B Kappa=0.62 (0.53-0.71) respectively ( P<0.0001 for both). The nurse, clinicians A and B indicated that of 94/116 (81.0%), 83/121 (68.6%) and 93/120 (77.5%) respectively required transfusion. HemoCue ® readings indicated anaemia as mild (Hb10.0-11.9g/dl) in 8/292 (2.7%), moderate (Hb5.0-9.9g/dl) in 132/292 (45.2%) and severe (Hb<5.0g/dl) in 152/292 (52.1%). Comparing to HemoCue® the Sahli's method performed best in estimation of severe anaemia, with sensitivity 84.0% and specificity 87.9% and a Kappa score of  0.70 (0.64-0.80). Conclusions: Clinical assessment of severe pallor results has a low specificity for the diagnosis of severe anaemia. To target blood transfusion Hb measurement by either Hemocue® or Sahli's method for the cost of USD 4 or and USD 0.25 per test, respectively would be more cost-effective.

An accurate and inexpensive color-based assay for detecting severe anemia in a limited-resource setting

Severe anemia is an important cause of morbidity and mortality among children in resource-poor settings, but laboratory diagnostics are often limited in these locations. To address this need, we developed a simple, inexpensive, and color-based point-of-care (POC) assay to detect severe anemia. The purpose of this study was to evaluate the accuracy of this novel POC assay to detect moderate and severe anemia in a limited-resource setting. The study was a cross-sectional study conducted on children with sickle cell anemia in Luanda, Angola. The hemoglobin concentrations obtained by the POC assay were compared to reference values measured by a calibrated automated hematology analyzer. A total of 86 samples were analyzed (mean hemoglobin concentration 6.6 g/dL). There was a strong correlation between the hemoglobin concentrations obtained by the POC assay and reference values obtained from an automated hematology analyzer (r=0.88, P<0.0001). The POC assay demonstrated excellent reproducibility (r=0.93, P<0.0001) and the reagents appeared to be durable in a tropical setting (r=0.93, P<0.0001). For the detection of severe anemia that may require blood transfusion (hemoglobin <5 g/dL), the POC assay had sensitivity of 88.9% and specificity of 98.7%. These data demonstrate that an inexpensive (<$0.25 USD) POC assay accurately estimates low hemoglobin concentrations and has the potential to become a transformational diagnostic tool for severe anemia in limited-resource settings.

Accuracy and Use of WHO Hemoglobin Color Scale for Diagnosis of Anemia Among Pregnant Women by Health Care Providers in Periurban Settings in Karachi, Pakistan

The study assessed the diagnostic accuracy of the Hemoglobin Color Scale (HCS), comparing clinical signs assessment technique (CSAT) of health care providers against the gold standard of laboratory hemoglobinometry. A cross-sectional validation study was conducted among 194 pregnant women located in 2 towns of periurban settings in Karachi, from June 2012 to February 2013. Anemia was assessed by HCS and CSAT by health care providers and compared with laboratory hemoglobinometry. The sensitivity and specificity of HCS were 70.9% (95% CI = 62.7-78.3) and 49.1% (95% CI = 35.1-63.2); for CSAT they were 95.7% (95% CI = 91.0-98.4) and 5.7% (95% CI = 1.2-15.7), respectively. The area under the curve for HCS for diagnosis of anemia was 0.60 (95% CI = 0.52-0.66), compared with 0.50 (95% CI = 0.43-0.57) for CSAT ( P = .01). The accuracy of HCS is better than CSAT for assessing anemia by health care providers among pregnant women.

The predictive value of current haemoglobin levels for incident tuberculosis and/or mortality during long-term antiretroviral therapy in South Africa: a cohort study

BACKGROUND

Low haemoglobin concentrations may be predictive of incident tuberculosis (TB) and death in HIV-infected patients receiving antiretroviral therapy (ART), but data are limited and inconsistent. We examined these relationships retrospectively in a long-term South African ART cohort with multiple time-updated haemoglobin measurements.

METHODS

Prospectively collected clinical data on patients receiving ART for up to 8 years in a community-based cohort were analysed. Time-updated haemoglobin concentrations, CD4 counts and HIV viral loads were recorded, and TB diagnoses and deaths from all causes were ascertained. Anaemia severity was classified using World Health Organization criteria. TB incidence and mortality rates were calculated and Poisson regression models were used to identify independent predictors of incident TB and mortality, respectively.

RESULTS

During a median follow-up of 5.0 years (IQR, 2.5-5.8) of 1,521 patients, 476 cases of incident TB and 192 deaths occurred during 6,459 person-years (PYs) of follow-up. TB incidence rates were strongly associated with time-updated anaemia severity; those without anaemia had a rate of 4.4 (95%CI, 3.8-5.1) cases/100 PYs compared to 10.0 (95%CI, 8.3-12.1), 26.6 (95%CI, 22.5-31.7) and 87.8 (95%CI, 57.0-138.2) cases/100 PYs in those with mild, moderate and severe anaemia, respectively. Similarly, mortality rates in those with no anaemia or mild, moderate and severe time-updated anaemia were 1.1 (95%CI, 0.8-1.5), 3.5 (95%CI, 2.7-4.8), 11.8 (95%CI, 9.5-14.8) and 28.2 (95%CI, 16.5-51.5) cases/100 PYs, respectively. Moderate and severe anaemia (time-updated) during ART were the strongest independent predictors for incident TB (adjusted IRR = 3.8 [95%CI, 3.0-4.8] and 8.2 [95%CI, 5.3-12.7], respectively) and for mortality (adjusted IRR = 6.0 [95%CI, 3.9-9.2] and adjusted IRR = 8.0 [95%CI, 3.9-16.4], respectively).

CONCLUSIONS

Increasing severity of anaemia was associated with exceptionally high rates of both incident TB and mortality during long-term ART. Patients receiving ART who have moderate or severe anaemia should be prioritized for TB screening using microbiological assays and may require adjunctive clinical interventions.

Implications of inconsistent anaemia policies for children and adolescents in Africa

OBJECTIVE

To evaluate the quality of policies concerning the diagnosis, treatment and prevention of anaemia in children and adolescents; to determine to what extent these are evidence-based; and to use this analysis to inform the policy-making process.

SUBJECTS

Children and adolescents in sub-Saharan Africa.

SETTING

Almost 50 % of children and adolescents in sub-Saharan Africa are anaemic, which has profound effects on their intellectual and physical development and their chance of survival. Evidence-based policies are essential to reduce anaemia but because it is caused by an array of interdependent factors, developing policies is challenging.

DESIGN

Forty-six policy documents concerning the diagnosis, treatment and prevention of anaemia in children and adolescents were identified and analysed.

RESULTS

There was policy consensus on the usefulness of Fe supplements, the need to treat co-morbidities and the use of blood transfusions for severe anaemia. Information about diagnosis was scarce, and messages regarding the control of anaemia were mixed. Few of the policies were tailored for the African context and they were located on several websites hosted by different health programmes.

CONCLUSIONS

The weakest aspects of the policies and consequently the priorities for better policy making were: lack of adherence to WHO recommendations for guideline development; little involvement of African practitioners/policy makers in the guideline group and as peer reviewers; and lack of harmonisation, demonstrating the need to establish a single body responsible for developing/revising anaemia policies.

Disposable platform provides visual and color-based point-of-care anemia self-testing

BACKGROUND

Anemia, or low blood hemoglobin (Hgb) levels, afflicts 2 billion people worldwide. Currently, Hgb levels are typically measured from blood samples using hematology analyzers, which are housed in hospitals, clinics, or commercial laboratories and require skilled technicians to operate. A reliable, inexpensive point-of-care (POC) Hgb test would enable cost-effective anemia screening and chronically anemic patients to self-monitor their disease. We present a rapid, stand-alone, and disposable POC anemia test that, via a single drop of blood, outputs color-based visual results that correlate with Hgb levels.

METHODS

We tested blood from 238 pediatric and adult patients with anemia of varying degrees and etiologies and compared hematology analyzer Hgb levels with POC Hgb levels, which were estimated via visual interpretation using a color scale and an optional smartphone app for automated analysis.

RESULTS

POC Hgb levels correlated with hematology analyzer Hgb levels (r = 0.864 and r = 0.856 for visual interpretation and smartphone app, respectively), and both POC test methods yielded comparable sensitivity and specificity for detecting any anemia (n = 178) (<11 g/dl) (sensitivity: 90.2% and 91.1%, specificity: 83.7% and 79.2%, respectively) and severe anemia (n = 10) (<7 g/dl) (sensitivity: 90.0% and 100%, specificity: 94.6% and 93.9%, respectively).

CONCLUSIONS

These results demonstrate the feasibility of this POC color-based diagnostic test for self-screening/self-monitoring of anemia.

TRIAL REGISTRATION

Not applicable.

FUNDING

This work was funded by the FDA-funded Atlantic Pediatric Device Consortium, the Georgia Research Alliance, Children's Healthcare of Atlanta, the Georgia Center of Innovation for Manufacturing, and the InVenture Prize and Ideas to Serve competitions at the Georgia Institute of Technology.

Global health care of the critically ill in low-resource settings

The care of the critically ill patient in low-resource settings is challenging because of many factors, including limitations in the existing infrastructure, lack of disposables, and low numbers of trained healthcare workers. Although cost constraints in low-resource settings have traditionally caused critical care to be relegated to a low priority, ethical issues and the potential for mitigation of the lethal effects of often reversible acute conditions, such as sepsis and traumatic hemorrhage, argue for prudent deployment of critical care resources. Given these challenges, issues that require prioritization include timely and reliable delivery of evidence-based or generally accepted interventions to acutely ill patients before the development of organ failure, context-specific adaptation and evaluation of clinical evidence, and sustained investments in quality improvement and health systems strengthening. Specific examples include fluid resuscitation algorithms for patients with sepsis and reliable, low-cost, high-flow oxygen concentrators for patients with pneumonia. The lessons from new research on clinical management and sustainable education and quality improvement approaches will likely improve the care of critically ill patients worldwide.

Validation of the WHO Hemoglobin Color Scale Method

This study was carried out to evaluate the diagnostic accuracy of WHO color scale in screening anemia during blood donor selection in Sri Lanka. A comparative cross-sectional study was conducted by the Medical Laboratory Sciences Unit of University of Sri Jayewardenepura in collaboration with National Blood Transfusion Centre, Sri Lanka. A total of 100 subjects participated in this study. Hemoglobin value of each participant was analyzed by both WHO color scale method and cyanmethemoglobin method. Bland-Altman plot was used to determine the agreement between the two methods. Sensitivity, specificity, predictive values, false positive, and negative rates were calculated. The sensitivity of the WHO color scale was very low. The highest sensitivity observed was 55.55% in hemoglobin concentrations >13.1 g/dL and the lowest was 28.57% in hemoglobin concentrations between 7.1 and 9.0 g/dL. The mean difference between the WHO color scale and the cyanmethemoglobin method was 0.2 g/dL (95% confidence interval; 3.2 g/dL above and 2.8 g/dL below). Even though the WHO color scale is an inexpensive and portable method for field studies, from the overall results in this study it is concluded that WHO color scale is an inaccurate method to screen anemia during blood donations.

Prevalence and socio-demographic factors associated with anaemia in pregnancy in a primary health centre in Rivers State, Nigeria

Background: Anaemia, though a common problem in Nigeria, has not been adequately studied amongst pregnant women in primary health care facilities. Objective: This study is aimed at determining the prevalence of anaemia and sociodemographic factors associated with anaemia in pregnancy in a primary health centre in Rivers State, Nigeria.Methodology: This is a cross-sectional study carried out in a primary health centre. Association between variables was analysed using the Chi-square test.Results: Two hundred and twenty-seven pregnant women whose ages ranged from 16 to 40 years with a mean age of 26.8 ± 4.3 years were recruited for the study. The haemoglobin concentration ranged from 6 g/dL – 15 g/dL with a mean of 10.10 ± 1.27g/dL. A total of 142 (62.6%) participants were anaemic. Anaemia was observed to be least prevalent in women within the extremes of reproductive age (≤ 20 years and 36–40 years). There was no statistically significant association between age, educational level and marital status (p > 0.05). The association of anaemia with social class was statistically significant (p = 0.000). Severe anaemia was not a common finding amongst the patients but it was significantly associated with educational status (p = 0.02) and socio-economic status (p = 0.03).Conclusion: The prevalence of anaemia amongst the pregnant participants in the primary health centre was high. Out of all the socio-demographic characteristics, only socio-economic status was significantly associated with anaemia. It is recommended that the socio-economic status of women should be enhanced in line with the Millennium Development Goals to prevent anaemia and to enhance pregnancy outcomes.

A single sea lamprey attack causes acute anemia and mortality in lake sturgeon

The effects of sea lamprey Petromyzon marinus parasitism on hematological variables have not been quantified for lake sturgeon Acipenser fulvescens. Our study objectives were to (1) assess changes in lake sturgeon hematology immediately after a single sea lamprey attack and after a 2-week recovery period and (2) assess changes in the histological condition of major hematopoietic organs. Lake sturgeon from four size-groups (470-570, 570-650, 650-760, and 950-1,500 mm fork length) were individually subjected to a sea lamprey attack in a series of 55 experimental trials. Survival of lake sturgeon after a single sea lamprey attack was size dependent, with fish in smaller size-groups exhibiting higher direct and indirect mortality than individuals in larger size-classes. The most sensitive blood chemistry variable was hematocrit: each 1% decline in hematocrit resulted in a 5.1% increase in mortality risk. Other important variables were plasma protein level, with a 10-g/dL decline resulting in a 4.2% increase in mortality risk; and hemoglobin, with a 1-g/dL decline resulting in a 2.9% increase in mortality risk. Most of the surviving lake sturgeon were unable to restore hemoglobin, hematocrit, and plasma protein to pre-attack levels by the end of the 2-week recovery period. We developed an index of histological spleen condition, which indicated that short-duration (< 5-d) sea lamprey attachments depleted red blood cell reserves faster than longer-duration attacks. Our study results indicate that sea lamprey parasitism has the potential to induce acute anemia in lake sturgeon and that nonlethal attacks on smaller (< 760-mm) fish can have serious physiological implications.

Evaluation of the diagnostic accuracy of the Haemoglobin Colour Scale to detect anaemia in young children attending primary healthcare clinics in Zanzibar

OBJECTIVES

This study evaluates the diagnostic accuracy of Haemoglobin Colour Scale (HCS), compared with clinical diagnosis, to detect anaemia and severe anaemia in preschool-age children attending primary healthcare clinics in rural Zanzibar.

METHODS

In all participants, haemoglobin (Hb) concentration was independently estimated by clinical examination for palmar pallor, HCS and HemoCue™. HemoCue was considered the reference method. Data collection was integrated into the usual health services and performed by local healthcare workers (HCWs). Sensitivity, specificity, positive and negative predictive values were calculated for HCS and clinical examination for palmar pallor. The limits of agreement between HCS and HemoCue, and inter-observer variability for HCS, were also defined.

RESULTS

A total of 799 children age 2-59 months were recruited to the study. The prevalence of anaemia (Hb<11 g/dl) and severe anaemia (<5 g/dl) were 71% and 0.8% respectively. The sensitivity of HCS to detect anaemia was 33% [95% confidence interval (CI) 29-36] and specificity was 87% (83-91). The sensitivity of HCS to detect severe anaemia was 14% (95% CI 0-58) and specificity was 100% (99-100). The sensitivity of palmar pallor to detect anaemia was low, but superior to HCS (58% vs. 33%, P<0.001); specificity was inferior to HCS (55% vs. 87%, P<0.001). There was no evidence of a difference in either sensitivity (P>0.1) or specificity (P>0.1) between HCS and palmar pallor to detect severe anaemia.

CONCLUSIONS

Haemoglobin Colour Scale does not improve the capacity of HCWs to diagnose anaemia in this population. Accuracy is limited by considerable variability in the performances of test operators. However, optimizing the training protocol for those using the test may improve performance.

Anaemia in pregnancy

Anaemia in pregnancy, defined as a haemoglobin concentration (Hb) < 110 g/L, affects more than 56 million women globally, two thirds of them being from Asia. Multiple factors lead to anaemia in pregnancy, nutritional iron deficiency anaemia (IDA) being the commonest. Underlying inflammatory conditions, physiological haemodilution and several factors affecting Hb and iron status in pregnancy lead to difficulties in establishing a definitive diagnosis. IDA is associated with increased maternal and perinatal morbidity and mortality, and long-term adverse effects in the new born. Strategies to prevent anaemia in pregnancy and its adverse effects include treatment of underlying conditions, iron and folate supplementation given weekly for all menstruating women including adolescents and daily for women during pregnancy and the post partum period, and delayed clamping of the umbilical cord at delivery. Oral iron is preferable to intravenous therapy for treatment of IDA. B12 and folate deficiencies in pregnancy are rare and may be due to inadequate dietary intake with the latter being more common. These vitamins play an important role in embryo genesis and hence any relative deficiencies may result in congenital abnormalities. Finding the underlying cause are crucial to the management of these deficiencies. Haemolytic anaemias rare also rare in pregnancy, but may have life-threatening complications if the diagnosis is not made in good time and acted upon appropriately.

Severe acquired anaemia in Africa: new concepts

Severe anaemia is common in Africa. It has a high mortality and particularly affects young children and pregnant women. Recent research provides new insights into the mechanisms and causes of severe acquired anaemia and overturns accepted dogma. Deficiencies of vitamin B12 and vitamin A, but not of iron or folic acid, are associated with severe anaemia. Bacterial infections and, in very young children, hookworm infections are also common in severe anaemia. Irrespective of the aetiology, the mechanism causing severe anaemia is often red cell production failure. Severe anaemia in Africa is therefore a complex multi-factorial syndrome, which, even in an individual patient, is unlikely to be amenable to a single intervention. Policies and practices concerning anaemia diagnosis, treatment and prevention need to be substantially revised if we are to make a significant impact on the huge burden of severe anaemia in Africa.

The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration

Systematic reviews and meta-analyses are essential to summarize evidence relating to efficacy and safety of health care interventions accurately and reliably. The clarity and transparency of these reports, however, is not optimal. Poor reporting of systematic reviews diminishes their value to clinicians, policy makers, and other users.Since the development of the QUOROM (QUality Of Reporting Of Meta-analysis) Statement--a reporting guideline published in 1999--there have been several conceptual, methodological, and practical advances regarding the conduct and reporting of systematic reviews and meta-analyses. Also, reviews of published systematic reviews have found that key information about these studies is often poorly reported. Realizing these issues, an international group that included experienced authors and methodologists developed PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) as an evolution of the original QUOROM guideline for systematic reviews and meta-analyses of evaluations of health care interventions.The PRISMA Statement consists of a 27-item checklist and a four-phase flow diagram. The checklist includes items deemed essential for transparent reporting of a systematic review. In this Explanation and Elaboration document, we explain the meaning and rationale for each checklist item. For each item, we include an example of good reporting and, where possible, references to relevant empirical studies and methodological literature. The PRISMA Statement, this document, and the associated Web site (http://www.prisma-statement.org/) should be helpful resources to improve reporting of systematic reviews and meta-analyses.

The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: explanation and elaboration

Systematic reviews and meta-analyses are essential to summarise evidence relating to efficacy and safety of healthcare interventions accurately and reliably. The clarity and transparency of these reports, however, are not optimal. Poor reporting of systematic reviews diminishes their value to clinicians, policy makers, and other users. Since the development of the QUOROM (quality of reporting of meta-analysis) statement-a reporting guideline published in 1999-there have been several conceptual, methodological, and practical advances regarding the conduct and reporting of systematic reviews and meta-analyses. Also, reviews of published systematic reviews have found that key information about these studies is often poorly reported. Realising these issues, an international group that included experienced authors and methodologists developed PRISMA (preferred reporting items for systematic reviews and meta-analyses) as an evolution of the original QUOROM guideline for systematic reviews and meta-analyses of evaluations of health care interventions. The PRISMA statement consists of a 27-item checklist and a four-phase flow diagram. The checklist includes items deemed essential for transparent reporting of a systematic review. In this explanation and elaboration document, we explain the meaning and rationale for each checklist item. For each item, we include an example of good reporting and, where possible, references to relevant empirical studies and methodological literature. The PRISMA statement, this document, and the associated website (www.prisma-statement.org/) should be helpful resources to improve reporting of systematic reviews and meta-analyses.

Anaemia: a useful indicator of neglected disease burden and control

The authors argue that one way of evaluating the effectiveness of an intervention aimed at controlling neglected tropical diseases would be to assess its impact on anemia prevalence.

Comparing FAMACHA eye color chart and Hemoglobin Color Scale tests for detecting anemia and improving treatment of bovine trypanosomosis in West Africa

African animal trypanosomosis (AAT) is considered the most important cattle disease in sub-Saharan Africa but its diagnosis in the field is difficult, resulting in inappropriate treatments, excessive delay in treatments and under-treatment. A field study in West Africa investigated the usefulness of anemia in the diagnosis of trypanosomosis. A total of 20,772 cattle blood samples were taken from 121 villages in 3 countries. The average packed cell volume (PCV) of trypanosomosis positive cattle was 23%, versus 28% for negative cattle. In a sub-set of animals, other causes of anemia were investigated showing most of the anemia burden was attributable to trypanosomosis. Anemia was a reasonably accurate indicator of trypanosomosis in the study area, with a sensitivity of 56% and a specificity of 80% and a diagnostic odds ratio of 4.2, the highest of all the signs evaluated (anemia, emaciation, staring coat, lymphadenopathy, fever, lacrimation and salivary or nasal discharge). Having confirmed the usefulness of anemia as a predictor of trypanosomosis, two potential pen-side tests for anemia were evaluated (the first reported trial of their use in cattle), firstly a color chart developed for anemia detection in sheep through visual inspection of conjunctival membranes (FAMACHA) and secondly the Hemoglobin Color Scale (HbCS) developed for assessing hemoglobin levels in human patients by comparing blood drops on filter paper with color standards. In a population of cattle suspected by their owners to be sick with trypanosomosis (n=898) the sensitivity of the HbCS test was 56% and the specificity was 77%, while the sensitivity of the FAMACHA test was 95% and the specificity was 22%. The higher sensitivity but lower specificity suggests the FAMACHA may be useful as a screening test and the HbCS as a confirmatory test. The two tests were also evaluated in cattle randomly selected from the village herd. Using cut-off points to optimize test performance, the HbCS test had a sensitivity of 81% and a specificity of 62% (n=505 cattle), while the FAMACHA had a sensitivity of 92% and a specificity of 30% (n=298 cattle). Recommendations are made for the appropriate use of these tests in the West African region.

Evaluation of the WHO Haemoglobin Colour Scale for diagnosis of anaemia in children and pregnant women as used by primary health care nurses and community health workers in western Kenya

OBJECTIVES

To evaluate the diagnostic accuracy of the WHO Haemoglobin Colour Scale (HCS) for anaemia in three groups of children aged 2 months to 2 years (sick children, those visiting an immunization clinic and a community-based random sample of children) and a sample of pregnant women.

METHODS

Finger-prick blood samples were taken from all consenting participants. Haemoglobin (Hb) levels from the HCS were compared with results from a HemoCue portable haemoglobinometer. Sensitivity, specificity and positive and negative predictive values for the HCS were calculated.

RESULTS

A total of 457 sick children, 336 children visiting immunization clinics, 454 children from the community at large and 643 pregnant women participated. The prevalence of anaemia (Hb<11 g/dl) in these groups was 87%, 79%, 74% and 52%, respectively. The prevalence of severe anaemia (Hb<7 g/dl) was 24%, 11%, 10% and 2%, respectively. The sensitivity of the HCS for anaemia ranged from 60% to 79% and specificity from 59% to 94%. The sensitivity of the HCS for severe anaemia ranged from 24% to 63% and the specificity from 97% to 100%. Through use of the HCS, the proportion of sick, anaemic children visiting peripheral health facilities diagnosed and treated for anaemia would increase from 3% to 65%.

CONCLUSIONS

In an area with high prevalence of anaemia among sick children, use of the HCS has the potential to significantly increase the proportion of sick, anaemic children who are diagnosed with anaemia and given appropriate treatment. Further evaluations of the effect of the use of the HCS on treatment practices at the health facility level are required.