Clinical use of WHO haemoglobin colour scale: validation and critique

Validation of ToucHb, a non-invasive haemoglobin estimation: Effective for normal ranges, needs improvement for anaemia detection

Non-invasive methods for haemoglobin estimation hold enormous potential for early detection and treatment of anaemia, especially in limited resource settings. We sought to validate the diagnostic accuracy of ToucHb, a non-invasive haemoglobin estimation device available in the Indian market. We prospectively evaluated the diagnostic performance of the ToucHb device using the Automated complete blood count (CBC) method as the gold standard. Persons referred for haemoglobin estimation to the central laboratory of the government medical college hospital in Mysore, southern India were included in the study. Out Of 140 people approached, 127 gave consent; 65% (n = 82) were female with median age of 37 (IQR 28-45). ToucHB reported median haemoglobin value of 14 g/dL compared to 13.3 g/dL for CBC. Within 1 g/dL and 2 g/dL of CBC, 55.2% (70/127) and 74% (94/127) of ToucHb haemoglobin observations fell, respectively. The Bland-Altman plot showed a mean difference of 3 g/dL in haemoglobin between ToucHb and CBC among those with anaemia. The ToucHb device showed 22.2% sensitivity and 94.5% specificity for anaemia detection. In rural resource-limited settings, point of care non-invasive devices such as ToucHb can improve access and acceptance for anaemia screening. However, ToucHb has showed low sensitivity for anaemia detection and low accuracy at lower haemoglobin values. The utility of the instrument is especially limited in detecting anaemia, while it can estimate haemoglobin accurately among those with haemoglobin is in the normal range. Based on these findings, ToucHb and devices that work on the core technology deployed in ToucHb may be better suited to monitor known haemoglobin level rather than in anaemia screening or detection in primary/ secondary care and community settings.

Human Milk Calorie Guide: A Novel Color-Based Tool to Estimate the Calorie Content of Human Milk for Preterm Infants

Fixed-dose fortification of human milk (HM) is insufficient to meet the nutrient requirements of preterm infants. Commercial human milk analyzers (HMA) to individually fortify HM are unavailable in most centers. We describe the development and validation of a bedside color-based tool called the 'human milk calorie guide'(HMCG) for differentiating low-calorie HM using commercial HMA as the gold standard. Mothers of preterm babies (birth weight ≤ 1500 g or gestation ≤ 34 weeks) were enrolled. The final color tool had nine color shades arranged as three rows of three shades each (rows A, B, and C). We hypothesized that calorie values for HM samples would increase with increasing 'yellowness' predictably from row A to C. One hundred thirty-one mother's own milk (MOM) and 136 donor human milk (DHM) samples (total n = 267) were color matched and analyzed for macronutrients. The HMCG tool performed best in DHM samples for predicting lower calories (<55 kcal/dL) (AUC 0.87 for category A DHM) with modest accuracy for >70 kcal/dL (AUC 0.77 for category C DHM). For MOM, its diagnostic performance was poor. The tool showed good inter-rater reliability (Krippendorff's alpha = 0.80). The HMCG was reliable in predicting lower calorie ranges for DHM and has the potential for improving donor HM fortification practices.

Safety monitoring experience of single-low dose primaquine co-administered with artemether-lumefantrine among providers and patients in routine healthcare practice: a qualitative study in Eastern Tanzania

Background

Primaquine is a gametocytocidal drug recommended by the World Health Organization (WHO) in a single-low dose combined with artemisinin-based combination therapy (ACT) for the treatment and prevention of Plasmodium falciparum malaria transmission. Safety monitoring concerns and the lack of a universal validated and approved primaquine pharmacovigilance tool is a challenge for a national rollout in many countries. This study aimed to explore the acceptance, reliability and perceived effectiveness of the primaquine roll out monitoring pharmacovigilance tool (PROMPT).

Methods

This study was conducted in three dispensaries in the Coastal region of Eastern Tanzania. The study held six in-depth interviews with healthcare providers and six participatory focus group discussions with malaria patients (3) and parents/guardians of sick children (3). Participants were purposively sampled. Thematic analysis was conducted with the aid of NVivo qualitative analysis software.

Results

The respondents’ general acceptance and perceived effectiveness of the single-low dose primaquine and PROMPT was good. Screening procedure for treatment eligibility and explaining to patients about the possible adverse events was considered very useful for safety reasons. Crushing and dissolving of primaquine tablet to get the appropriate dose, particularly in children, was reported by all providers to be challenging. Transport costs and poor access to the health facility were the main reasons for a patient failing to return to the clinic for a scheduled follow-up visit. Treatment was perceived to be safe by both providers and patients and reported no case of a severe adverse event. Some providers were concerned with the haemoglobin drop observed on day 7.

Conclusion

Single-low dose primaquine was perceived to be safe and acceptable among providers and patients. PROMPT demonstrated to be a reliable and user-friendly tool among providers. Further validation of the tool by involving the National Malaria Control Programme is pivotal to addressing key challenges and facilitating primaquine adoption in the national policy.

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.

Methods and analyzers for hemoglobin measurement in clinical laboratories and field settings

This paper describes and compares methods and analyzers used to measure hemoglobin (Hb) in clinical laboratories and field settings. We conducted a literature review for methods used to measure Hb in clinical laboratories and field settings. We described methods to measure Hb and factors influencing results. Automated hematology analyzer (AHA) was reference for all Hb comparisons using evaluation criteria of ±7% set by College of American Pathologists (CAP) and Clinical Laboratory Improvement Amendments (CLIA). Capillary fingerprick blood usually produces higher Hb concentrations compared with venous blood. Individual drops produced lower concentrations than pooled capillary blood. Compared with the AHA: (1) overall cyanmethemoglobin (1.0-8.0  g/L), WHO Colour Scale (0.5-10.0  g/L), paper-based devices (5.0-7.0  g/L), HemoCue® Hb-201 (1.0-16.0  g/L) and Hb-301 (0.5-6.0  g/L), and Masimo Pronto® (0.3-14.0  g/L) overestimated concentrations; (2) Masimo Radical®-7 both under- and overestimated concentrations (0.3-104.0  g/L); and (3) other methods underestimated concentrations (2.0-16.0  g/L). Most mean concentration comparisons varied less than ±7% of the reference. Hb measurements are influenced by several analytical factors. With few exceptions, mean concentration bias was within ±7%, suggesting acceptable performance. Appropriate, high-quality methods in all settings are necessary to ensure the accuracy of Hb measurements.This paper describes and compares methods and analyzers used to measure hemoglobin (Hb) in clinical laboratories and field settings. With few exceptions, mean concentration bias was within ±7%, suggesting acceptable performance. Appropriate, high-quality methods in all settings are necessary to ensure the accuracy of Hb measurements.

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.

Prevalence of Portable Point of Care Tests Used on Medical Service Trips in Latin America and the Caribbean

Background:

Short-term, primary care medical service trips (MSTs) frequently use inexpensive, portable point of care (POC) tests to guide diagnosis and treatment of patients in low-resource settings. However, the degree to which different POC tests are carried by organizations serving remote communities is currently unknown.

Objective:

The aim of this study was to determine the prevalence of various POC tests used by MST-sending organizations operating in Latin America.

Methods:

We surveyed 166 organizations operating mobile MSTs in Latin America and the Caribbean on the types of POC tests carried on their brigades.

Findings:

Forty-eight organizations responded (response rate: 28.9%). The most commonly carried tests were glucometers (40/48; 83.3%), urine dipsticks (31/48; 77.1%), and urine pregnancy tests (32/48; 66.7%). Fewer groups carried hemoglobinometers (16/48; 33.3%), malaria diagnostic tests (18/48; 37.5%), tests for sexually transmitted infection (8/48; 16.7%), or portable ultrasound (19/48; 40.0%).

Conclusions:

These tests may be useful for field diagnosis, but clinicians should understand the performance limitations of each test compared to its gold standard. When combined with knowledge of local epidemiology, these exploratory results will be useful in resource planning, guidelines development for MSTs, and in establishing minimum recommendations for diagnostic resources that should be available on MSTs.

Prevalence of Portable Point of Care Tests Used on Medical Service Trips in Latin America and the Caribbean

BACKGROUND

Short-term, primary care medical service trips (MSTs) frequently use inexpensive, portable point of care (POC) tests to guide diagnosis and treatment of patients in low-resource settings. However, the degree to which different POC tests are carried by organizations serving remote communities is currently unknown.

OBJECTIVE

The aim of this study was to determine the prevalence of various POC tests used by MST-sending organizations operating in Latin America.

METHODS

We surveyed 166 organizations operating mobile MSTs in Latin America and the Caribbean on the types of POC tests carried on their brigades.

FINDINGS

Forty-eight organizations responded (response rate: 28.9%). The most commonly carried tests were glucometers (40/48; 83.3%), urine dipsticks (31/48; 77.1%), and urine pregnancy tests (32/48; 66.7%). Fewer groups carried hemoglobinometers (16/48; 33.3%), malaria diagnostic tests (18/48; 37.5%), tests for sexually transmitted infection (8/48; 16.7%), or portable ultrasound (19/48; 40.0%).

CONCLUSIONS

These tests may be useful for field diagnosis, but clinicians should understand the performance limitations of each test compared to its gold standard. When combined with knowledge of local epidemiology, these exploratory results will be useful in resource planning, guidelines development for MSTs, and in establishing minimum recommendations for diagnostic resources that should be available on MSTs.

3D printed microfluidic mixer for point-of-care diagnosis of anemia

3D printing has been an emerging fabrication tool in prototyping and manufacturing. We demonstrated a 3D microfluidic simulation guided computer design and 3D printer prototyping for quick turnaround development of microfluidic 3D mixers, which allows fast self-mixing of reagents with blood through capillary force. Combined with smartphone, the point-of-care diagnosis of anemia from finger-prick blood has been successfully implemented and showed consistent results with clinical measurements. Capable of 3D fabrication flexibility and smartphone compatibility, this work presents a novel diagnostic strategy for advancing personalized medicine and mobile healthcare.

3D printed auto-mixing chip enables rapid smartphone diagnosis of anemia

Clinical diagnosis requiring central facilities and site visits can be burdensome for patients in resource-limited or rural areas. Therefore, development of a low-cost test that utilizes smartphone data collection and transmission would beneficially enable disease self-management and point-of-care (POC) diagnosis. In this paper, we introduce a low-cost iPOC^3D diagnostic strategy which integrates 3D design and printing of microfluidic POC device with smartphone-based disease diagnosis in one process as a stand-alone system, offering strong adaptability for establishing diagnostic capacity in resource-limited areas and low-income countries. We employ smartphone output (AutoCAD 360 app) and readout (color-scale analytical app written in-house) functionalities for rapid 3D printing of microfluidic auto-mixers and colorimetric detection of blood hemoglobin levels. The auto-mixing of reagents with blood via capillary force has been demonstrated in 1 second without the requirement of external pumps. We employed this iPOC^3D system for point-of-care diagnosis of anemia using a training set of patients (n_anemia = 16 and n_healthy = 6), which showed consistent measurements of blood hemoglobin levels (a.u.c. = 0.97) and comparable diagnostic sensitivity and specificity, compared with standard clinical hematology analyzer. Capable of 3D fabrication flexibility and smartphone compatibility, this work presents a novel diagnostic strategy for advancing personalized medicine and mobile healthcare.

How valid is the tallquist method in screening pregnant women with anemia in poor rural settings of southwestern Nigeria?

BACKGROUND

Diagnosis of anemia is challenging in resource-poor settings due to inadequate laboratory resources. This study assessed the validity of the Tallquist haemoglobinometer in assessing anemia among pregnant women in Osogbo, Southwestern Nigeria.

METHODS

This was a cross - sectional study, in which 200 pregnant women of reproductive age were selected using multistage sapling method. A checklist was used to collect socio-demographic data and the results of the screening test. Blood collection and analysis were carried out using standardized referenced methods.

RESULTS

Mean±SD age of the respondents was 28.9+3.9 yrs.; and 62 (62.6%) had up to primary level education. When Tallquist and Haematocrit methods were compared, there was 68.4%, 83.5% and 100% likelihood of Tallquist method (TM) diagnosing severe, moderate and mild anemia, respectively. The validity indices of the TM versus Haematocrit method as the gold standard revealed the sensitivity of 97.9%, specificity of 92.1%, positive predictive value of 92.4%, and negative predictive value of 97.9% and diagnostic accuracy of 95.0%. When compared to the Haemoglobin Cyanide method, the Tallquist method showed a calculated sensitivity of 96.6%, specificity of 87.4%, positive predictive value of 86.0%, and negative predictive value of 97.0% and diagnostic accuracy of 91.5%.

CONCLUSION

The TM is a valid tool in screening anemia among pregnant women in resource- poor settings and rural primary health care centers in Southwestern Nigeria; therefore, its use should be encouraged, particularly to assess mild to moderate anemia.

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.

Validity of Palmar Pallor for Diagnosis of Anemia among Children Aged 6-59 Months in North India

Introduction. The Integrated Management of Childhood and Neonatal Illness (IMNCI) recommends the use palmar pallor to diagnose anaemia. Earlier studies to validate palmar pallor as clinical sign for anaemia were largely done in African context. There was a need to test validity of palmar pallor to detect anemia in different settings. Objective. To study the validity and interobserver agreement of palmar pallor examination to diagnose anemia in children under 5 years of age in India. Methods. In a village in Northern India, hemoglobin estimation was done for 80 children using cyanomethemoglobin method. Two examiners, a physician and a health worker, trained in IMNCI evaluated children for palmar pallor. Sensitivity and specificity and Kappa statistics were calculated. Results. Health worker diagnosed palmar pallor with sensitivity of 30.8–42.8% and specificity of 70–89%. Similar figures for doctor were 40–47% and 60–66%, respectively. Kappa agreement between a health worker and a physician was 0.48 (95% CI = 0.298–0.666) and then increased to 0.51 when categories of severe pallor and mild pallor were merged. Conclusion. While using palmar pallor as clinical sign for anaemia, children with no pallor should also be followed up closely for possible detection of missed cases during follow-up.

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.

Validation of the haemoglobin colour scale for screening blood donors in Malawi

BACKGROUND

In 2009 Malawi introduced a new protocol to screen potential blood donors for anaemia, using the WHO Haemoglobin Colour Scale (HCS) for initial screening. Published studies of the accuracy of the HCS to screen potential blood donors show varying levels of accuracy and opinion varies whether this is an appropriate screening test. The aim of the study was to assess the validity of the HCS, as a screening test, by comparison to HemoCue in potential blood donors in Malawi.

STUDY DESIGN AND METHODS

This was a blinded prospective study in potential blood donors aged over 18 years, at Malawi Blood Transfusion Service in Blantyre, Malawi. Capillary blood samples were analysed using the HCS and HemoCue, independent of each other. The sensitivity and specificity of correctly identifying ineligible blood donors (Hb ≤ 12 g/dL) were calculated.

RESULTS

From 242 participants 234 (96.7%) were correctly allocated and 8 (3.3%), were wrongly allocated on the basis of the Haemoglobin Colour Scale (HCS) compared to HemoCue, all were subjects that were wrongly accepted as donors when their haemoglobin results were ≤ 12.0 g/dL. This gave a sensitivity of 100% and specificity of 96.7% to detect donor eligibilty. The negative predictive value of the HCS was 100% but the positive predictive value to identify ineligible donors on the basis of anaemia was only 20%.

CONCLUSIONS

Initial screening with the HCS correctly predicts eligibility for blood donation in the majority of potential blood donors at considerable cost saving compared with use of HemoCue as the first line anaemia screening test, however, by this method a small number of anaemic patients were allowed to donate blood.

Assessing diagnostic accuracy of Haemoglobin Colour Scale in real-life setting

The study was undertaken to determine diagnostic accuracy of Haemoglobin Colour Scale (HCS) in hands of village-based community health workers (CHWs) in real-life community setting in India. Participants (501 women) were randomly selected from 8 villages belonging to a project area of SEWA-Rural, a voluntary organization located in India. After receiving a brief training, CHWs and a research assistant obtained haemoglobin readings using HCS and HemoCue (reference) respectively. Sensitivity, specificity, positive and negative predictive-values, and likelihood ratios were calculated. Bland-Altman plot was constructed. Mean haemoglobin value, using HCS and HemoCue were 11.02 g/dL (CI 10.9-11.2) and 11.07 g/dL (CI 10.9-11.2) respectively. Mean difference between haemoglobin readings was 0.95 g/dL. Sensitivity of HCS was 0.74 (CI 0.65-0.81) and 0.84 (CI 0.8-0.87) whereas specificity was 0.84 (CI:0.51-0.98) and 0.99 (CI:0.97-0.99) using haemoglobin cutoff limits of 10 g/dL and 7 g/dL respectively. CHWs can accurately diagnose severe and moderately-severe anaemia by using HCS in real-life field condition after a brief training.

Iron deficiency anemia: a common and curable disease

Iron deficiency anemia arises when the balance of iron intake, iron stores, and the body's loss of iron are insufficient to fully support production of erythrocytes. Iron deficiency anemia rarely causes death, but the impact on human health is significant. In the developed world, this disease is easily identified and treated, but frequently overlooked by physicians. In contrast, it is a health problem that affects major portions of the population in underdeveloped countries. Overall, the prevention and successful treatment for iron deficiency anemia remains woefully insufficient worldwide, especially among underprivileged women and children. Here, clinical and laboratory features of the disease are discussed, and then focus is placed on relevant economic, environmental, infectious, and genetic factors that converge among global populations.

Quality evaluation of four hemoglobin screening methods in a blood donor setting along with their comparative cost analysis in an Indian scenario

Background:

Despite the wide range of methods available for measurement of hemoglobin, no single technique has emerged as the most appropriate and ideal for a blood donation setup.

Materials and Methods:

A prospective study utilizing 1014 blood samples was carried out in a blood donation setting for quality evaluation of four methods of hemoglobin estimation along with cost analysis: Hematology cell analyzer (reference), HCS, CuSO4 method and HemoCue.

Results:

Mean value of HemoCue (mean ± SD = 14.7 ± 1.49 g/dl) was higher by 0.24 compared to reference (mean ± SD = 13.8 ± 1.52 g/dl) but not statistically significant ( P > 0.05). HemoCue proved to be the best technique (sensitivity 99.4% and specificity 84.4%) whereas HCS was most subjective with 25.2% incorrect estimations. CuSO4 proved to be good with 7.9% false results. Comparative cost analysis of each method was calculated to be 35 INR/test for HemoCue, 0.76 INR /test for HCS and 0.06-0.08 INR /test for CuSO4.

Conclusion:

CuSO4 method gives accurate results, if strict quality control is applied. HemoCue is too expensive to be used as a primary screening method in an economically restricted country like India.

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.

Diagnostic accuracy comparison between clinical signs and hemoglobin color scale as screening methods in the diagnosis of anemia in children

OBJECTIVES: to compare the validity and reproducibility of clinical signs with the World Health Organization hemoglobin color scale. METHODS: Two hundred six children in the age range of 6-23 months, at the Instituto Materno Infantil Prof. Fernando Figueira, IMIP, were assessed. Two examiners evaluated the clinical signs and the hemoglobin color scale of each child at the different times. The hemoglobin value was used as a standard for validation. RESULTS: in more than 90% of cases the agreement between the values of the color scale and the laboratorial hemoglobin was <2 g/dL. Between the clinical signs the highest sensitivity level for diagnosing Hb<11 g/dL was presented by the hemoglobin color scale (75.7%). For moderate/severe anemia Hb<9g/dL the highest sensitivity was shown by combined palmar or conjunctival pallor (74.3%) and by the color scale (52.5%), according to the first and second observer, respectively. The highest specificity level for Hb<11 g/dL was presented by palmar pallor in comparison with the mother's palm and conjunctival pallor (100%). For Hb<9 g/dL the highest specificity was presented by the hemoglobin color scale (91.9%). CONCLUSIONS: this study suggests that moderate/severe anemia can be diagnosed either by clinical signs or by the color scale, while, in cases of mild anemia, the better diagnosis tool appears to be the color scale.

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.

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

BACKGROUND

Anaemia is a major public health problem, in poor countries most of the cases are diagnosed clinically. This is inaccurate and the haemoglobin colour scale (HCS) has been developed as an inexpensive, simple alternative for assessing anaemia. Laboratory and community studies have assessed its diagnostic accuracy, but controversy over its validity and usefulness remains. We carried out a systematic review to identify and summarize studies, explain heterogeneity, and make recommendations for future research.

METHODS

We searched electronic databases (MEDLINE, EMBASE, CINAHL, and Science Citation Index), checked documents and references, and contacted experts. We included all the studies comparing HCS diagnostic accuracy with a reference standard. Both reviewers independently screened titles and abstracts, assessed studies for inclusion, appraised quality, and extracted data.

RESULTS

We included 14 studies, mostly from sub-Saharan Africa. Studies had heterogeneous populations, health care settings, anaemia prevalence, and findings. HCS sensitivity for detecting anaemia was high in most of the studies (75-97%); specificity was generally lower (41-98%). Sensitivity and specificity were higher for laboratory-based studies compared with more pragmatic 'real-life' studies, and the 'study setting' appeared to explain some of the heterogeneity. Five studies compared the HCS with clinical diagnosis; sensitivity was higher for the HCS in four studies, but specificity was often higher with clinical diagnosis. A few studies evaluated the HCS in situations where there was no laboratory.

CONCLUSIONS

The HCS may improve anaemia diagnosis where there is no laboratory, but there is a need for policy-relevant diagnostic research which is pragmatic, implementation-focused and assesses clinical outcomes. This requires a different approach and research skill-mix from efficacy studies.

Haemoglobinometry in general practice

Haemoglobinometry as a primary point-of-care test is well established. This study was undertaken to assess whether haemoglobinometry by itself provides an adequate haematological screening procedure in general practice. In a series of 500 sequential blood counts received by the central hospital laboratory from local doctors, 405 (81%) had a normal haemoglobin. Full blood counts on these samples showed 15% with one or more blood count parameters outside 2SD of normal reference values, including increased MCV, low MCV with low MCH and MCHC, leucocytosis with neutrophilia, a few cases with neutropenia, lymphopenia, monocytosis or eosinophilia. When the limits were set at 3SD, these abnormalities were found in only 7.6% of the cases. Calculation of test utility gave a positive predictive value of 0.83, a negative predictive value of 0.85, with a likelihood ratio of 14.3 and an overall diagnostic reliability of 84%. It was concluded that haemoglobin alone is a valuable primary screening test and a full blood count is required only when anaemia is present or when the patient's history and clinical signs indicate the need for such further investigation. Using this protocol it is unlikely that any serious error will be made in diagnosing a clinically significant condition; the main limitation is failure to diagnose pre-anaemic iron deficiency.

Comparison of haemoglobinometry by WHO Haemoglobin Colour Scale and copper sulphate against haemiglobincyanide reference method

Although estimation of haemoglobin is essential for diagnosing anaemia and assessing its severity, many health centres in developing countries do not have the facilities for haemoglobinometry. The WHO Haemoglobin Colour Scale (HCS) method is a simple and inexpensive clinical device that was recently developed in order to diagnose anaemia in such centres. In Indonesia, the copper sulphate specific gravity method is used for blood donor screening and also in primary health clinics in the rural and remote areas. In this study, the HCS method is compared with the copper sulphate method and with an earlier paper scale, the Tallquist method, against the standard haemiglobincyanide spectrophotometric method. The HCS method showed an acceptable level of precision and accuracy for use as a reliable screening tool to diagnose anaemia in patients and also for blood donor screening.

Performance of the Haemoglobin Colour Scale in diagnosing severe and very severe anaemia

OBJECTIVE

To assess the accuracy of Haemoglobin Colour Scale (HCS) in identifying severely anaemic [haemoglobin (Hb) <7 g/dl] and very severely anaemic (Hb <5 g/dl) individuals, and to compare the performances of a group of health workers using HCS after training with a standard method.

METHOD

The study consisted of two parts. In part 1, the performance of HCS was compared with clinical examination in a hospital population of which more than 450 individuals were severely anaemic and more than 120 very severely anaemic. Part 2 of the study was conducted in eight dispensaries where the performances of 13 health workers using the colour scale were compared with the performances of eight other health workers using clinical signs to estimate Hb.

RESULTS

The colour scale was 92% sensitive for both severe anaemia and very severe anaemia and performed better than clinical examination. Health workers who used the colour scale did better in identifying anaemic and severely anaemic individuals, than those who used clinical examination.

CONCLUSIONS

The colour scale improves health workers' capacity to identify severely anaemic individuals and could be used as a basis for referral. Although the diagnostic accuracy of the workers using HCS varied widely, in most cases they did significantly better than those who used clinical investigation alone.

Comparison of screening methods for anaemia in pregnant women in Awassa, Ethiopia

Screening for anaemia in pregnancy is essential for implementing and monitoring effective antenatal programmes. We compared the diagnostic accuracy of invasive and non-invasive screening methods in a cross-sectional survey of 403 pregnant women attending an urban health centre in Awassa, southern Ethiopia. Overall anaemia prevalence [haemoglobin (Hb): <11 g/dl] was 15.1% (95% CI: 12.1-19.9), mild anaemia (Hb: 10-10.9 g/dl) 10.4%, moderate anaemia (Hb: 7-9.9 g/dl) 4.2% and severe anaemia (Hb < 7 g/dl) 0.3%. Sensitivity, specificity and predictive values of conjunctival pallor and the WHO Hb colour scale were calculated for Hb cut-off points <11, <10 and <9 g/dl. All methods in combination with the symptoms and complaints reported by the mothers were entered into a predictive scoring system. None of the methods tested or models predicted anaemia with suitable accuracy in this population. The diagnosis of anaemia based on clinical signs and symptoms remains unreliable despite attempts to develop predictive models.

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.

Laboratory practice at the periphery in developing countries

An effective national health service structure requires a comprehensive programme for primary health care in peripheral and rural areas. This is especially important in under-resourced countries where facilities are sparse, the population is widely dispersed and transport is limited. Haematology has a key role in diagnosis and patient management by selecting tests for their clinical relevance and utility for the specific circumstances, and ensuring their technical reliability when used in health clinics and point-of-care testing. WHO has proposed a basic menu of tests in three categories: (a) tests such as haemoglobin screen which can be performed by nurses, midwives, health-aides or community doctors, (b) tests such as haemoglobinometry, microhaematocrit and microscopic examination of stained preparations which can be performed by a technician or laboratory assistant in a health centre, (c) tests requiring greater technical expertise of a laboratory technician or trained doctor. The peripheral health clinics and district laboratories must be familiar with the guidelines on standardized methods for collecting and storing specimens and transporting them to a regional laboratory or a reference centre. A training syllabus should be provided at the health centres and district laboratories, and this should include on-site instruction from supervisors and access to training manuals and distance-learning material. A co-ordinated programme of quality assurance and standardization of test methods should be established by a reference centre or national health authority with a network which encompasses all laboratories and health clinics undertaking any tests. Each regional laboratory should foster lower level laboratories or clinics within its neighbourhood. Of particular concern is the reliable diagnosis and management of anaemia. WHO reports indicate that 40% of the world population suffer from anaemia, especially affecting pregnant women, and a high proportion of infants and children in developing countries. The Haemoglobin Colour Scale (HCS) was recently developed for WHO as a simple, cheap and portable device which reads haemoglobin within 1 g/dl of the true value. It has been validated in a number of studies and is now manufactured commercially in accordance with WHO specifications under control of a WHO Collaborating Centre. It has an important potential role in the resource-limited environment where anaemia screening presently usually depends on unreliable clinical examination.

Validity of the haemoglobin colour scale in blood donor screening

BACKGROUND AND OBJECTIVES

The haemoglobin colour scale (HCS) has been developed as a simple, reliable and inexpensive clinical device for diagnosing anaemia and estimating its severity when laboratory-based haemoglobinometry is not available. The purpose of this study was to assess its validity for screening blood donors for anaemia.

MATERIAL AND METHODS

The HCS was tested at five blood transfusion centres on a total of 2801 donors. Blood was obtained by skin puncture as part of the routine procedure at the donor sessions. HCS readings were compared with screening by the copper sulphate method, which was in routine use in the centres, and with haemoglobin (Hb) measurements by means of calibrated HemoCue haemoglobinometers. HCS readings were considered as normal when the readings were > or = 12 g/dl.

RESULTS

Analysis of the paired results showed that the HCS had an accuracy of 97.5% in distinguishing subjects with normal Hb from those below the acceptable limit, when checked against the HemoCue. The HCS was more reliable than the copper-sulphate specific-gravity method, yielding 3.7% false readings compared with 6.1% false readings, respectively. When discrimination was set at 12 g/dl with the HemoCue, the HCS gave an incorrect reading in 2.4% of donors. The majority of these false results (44 donors; 1.58%) were caused by the HCS indicating rejection of the donor (i.e. Hb < 12 g/dl) when the correct Hb was higher, whilst in 23 donors (0.82%) the HCS incorrectly indicated a normal Hb; however, in all but four of these donors the correct Hb values were 11.0-11.9 g/dl, and none were below 10 g/dl.

CONCLUSION

The operators were able to master the HCS technique after a few minutes of practice, and all found the test to be user friendly and easy to read. The HCS is proposed as a replacement for the copper sulphate method for blood transfusion donor selection.