Validation of a Point-of-care Screening Tool for Children With Sickle Cell Disease
Conditions: Sickle Cell Disease
Sponsor: University Hospitals Cleveland Medical Center

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PROTOCOL TITLE 
Validation of a point-of-care screening tool for children with sickle cell 
disease  
PRINCIPAL INVESTIGATOR: 
ADDRESS:  
TELEPHONE: 
EMAIL:  
SIGNATURE: ________________________ 

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ABSTRACT 
Background: Sickle cell disease (SCD) is the commonest genetic disorder in Nigeria, 
affecting up to 150,000 newborns per year. Given the high frequency of the HbS gene 
and the large population of affected children, high infant and under-5 mortality, it is 
estimated that SCD contributes at least 6% of all childhood mortality and of those affected, 
only 10% in sub Saharan Africa (SSA) are likely to reach adolescence. The clinical course 
of SCD is characterized by acute and chronic complications, which may be severe, 
leading to significant morbidity and mortality. Timely diagnosis is key to prevent or 
manage these complications. However, current diagnostic methods rely on laboratory 
systems that are expensive and time consuming or may even be unavailable. 
General Aim: The primary study objective is to validate the HemeChip technology as a 
rapid, point-of care (POC) platform for screening SCD. 
Methodology: This will be a single site cross-sectional study. 
Expected Outcome: The validation of the HemeChip technology as an affordable, 
robust, easy-to-use POC platform for screening of sickle cell disease (SCD).   

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1. BACKGROUND
1.1 Introduction 
Sickle cell disease (SCD) is a group of inherited disorders of haemoglobin (Hb) 
synthesis, first described in the medical literature by James Herrick in 1910. Each year 
about 300,000 infants are born with SCD, including more than 200,000 cases in sub-
Saharan Africa alone.1 In Nigeria, alone, there are over 150,000 of these children born 
annually and it is estimated that between 50-90% of these children die before their 
fifth birthday.2 Overall, in the region, 6% of all childhood mortality in children less than 
5 years of age is due to SCD complications and infections. Vaso occlusive crisis and 
anemia are serious complications of SCD, with infection often being the major cause 
of hospitalizations, crisis and death. 
SCD is caused by a point mutation in the sixth codon of the beta globin chain that 
produces normal Hb (HbA). This substitution of hydrophilic glutamic acid with 
hydrophobic valine produces sickle Hb (HbS), which is abnormally polymerized at low 
oxygen conditions causing sickling. Abnormal polymerization of HbS affects red cell 
membrane properties, shape, and density, and subsequent critical changes in 
inflammatory cell and endothelial cell function.3 The clinical consequences of SCD 
include painful crises, widespread organ damage, and early mortality.  
1.2  Problem statement 
Current standard practices for diagnosing SCD are high performance liquid 
chromatography (HPLC) and bench-top Hb electrophoresis. These two approaches, 
however, require trained personnel and state-of-the-art facilities, both of which may 
be lacking in many parts of sub-Saharan Africa where the disease is most prevalent.4 
These laboratory methods also carry significant costs which may be unaffordable for 
most patients. 
1.3  Relevance and Innovation 
HemeChip diagnostic system offers an original and innovative solution, leveraging a 
novel engineering approach, to point of care (POC) diagnosis of SCD. HemeChip 

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separates haemoglobin protein types in a miniscule volume of blood (1μL) on a piece 
of cellulose acetate paper that is housed in a micro-engineered chip with a controlled 
environment and electric field. Differences in Hb mobilities allow separation to occur 
within the cellulose acetate paper. A micro-engineered design and multiple layer 
lamination approach are utilized in fabricating the HemeChip. The design allows rapid 
manual assembly and results are available within a few minutes of performing the test. 
HemeChip can also integrate with a mobile user interface (e.g. IPhone, IPod), which 
shows the test result quantitatively and objectively on the screen. HemeChip can be 
used by anyone after a short (30 minute) training, eliminating the need for highly skilled 
personnel.  
2. AIMS
2.1  General objective  
The primary study objective is to validate the HemeChip technology as a novel, point-
of care (POC) platform for screening SCD. The results obtained using the HemeChip 
will be compared to High Performance Liquid Chromatography (HPLC), and the 
sensitivity and specificity of the HemeChip will be determined. 
2.2  Secondary objective 
i.
To determine the acceptability of using the HemeChip for POC screening of
SCD during clinical assessments.

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3. LITERATURE REVIEW
Despite its recognition as a global public health problem, SCD remains a neglected 
health priority in many low- and middle-income countries. Ironically, the burden of 
haemoglobinopathies is projected to increase in the coming decades. By 2050, it is 
estimated that the proportion of sickle cell anaemia births in sub-Saharan Africa will 
be about 88% of the worldwide total, compared to 79% in 2010. This increase will be 
largely as a result of population growth and public health transition.5
The pathophysiology of SCD includes premature red cell haemolysis, vascular 
obstruction, endothelial damage, chronic inflammation and infarction. These result in 
acute and chronic complications such as severe anaemia, bone pain, stroke and end 
organ damage.6,7 Complications may begin during infancy particularly in individuals 
with homozygous disease. Newborn screening for SCD has been shown to be highly 
effective in reducing the morbidity and mortality associated with SCD, when linked to 
comprehensive healthcare services.8,9 National programs for routine, universal 
newborn screening for SCD are lacking in many African countries, Nigeria inclusive.10 
Consequently, most children are diagnosed opportunistically, when they present to 
health facilities with clinical symptoms and signs suggestive of SCD.  
Standard diagnostic testing for sickle cell disease include cellulose acetate or citrate 
agar electrophoresis (bench top electrophoresis), IEF, high performance liquid 
chromatography (HPLC), capillary electrophoresis and molecular analysis.11  
Bench top Hb electrophoresis: This is a laboratory method that can be done under 
alkaline or acidic conditions and with a variety of sieving materials such as gel or 
paper.12 Under alkaline conditions, Hb types C, A2, S, F, and A have net negative 
charges and migrate towards the positively charged electrode forming visible bands 
that can be used to identify various Hb disorders. Although useful for the rapid 
screening of a small number of samples, its results may suffer from inaccuracies at 
low concentrations. Moreover, alkaline Hb electrophoresis has the disadvantage of 
having poor resolution between HbS and HbF, particularly in neonates who have high 
HbF levels, which may result in inaccurate identification of overlapping bands. 

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Isoelectric Focusing (IEF): IEF exploits the fact that the net charge of a protein varies 
with the pH of the surrounding medium. Utilizing this variation, proteins are separated 
based on their isoelectric points (pI), which can be defined as the point at which a 
protein possesses zero net charge. The technique uses an applied electric field across 
a gel medium with a fixed pH gradient, each Hb type becomes immobilized once it 
reaches its pI. IEF exhibits higher resolution than Hb electrophoresis, thus it is capable 
of distinguishing between a larger number of Hb variants. However, due to the larger 
number of bands that this higher resolution results in, IEF results are harder to 
interpret.12,13 IEF is also expensive and results can be inaccurate especially at low Hb 
concentrations. Despite these disadvantages, IEF is considered suitable for newborn 
screening since diagnosis is possible with very small sample volume or even an eluate 
from a dried blood spot.12 
High Performance Liquid Chromatography (HPLC): HPLC separates a fluid into its 
components based on size and charge using cation exchange chromatography to 
identify the various Hb types in a blood sample. Unique aspects of this test are full 
automation and accurate quantification of the Hb levels. These machines are relatively 
expensive and are not readily available in developing countries.4 In resource rich 
countries like the US, HPLC has largely replaced Hb electrophoresis and IEF as the 
gold standard.  
DNA Analysis: DNA-based assays can be used to detect the mutations in 𝛽 globin that 
produce abnormal Hb.14 However, it is generally more expensive than the previously 
described methods and is most often used for prenatal testing rather than 
postpartum.15  
HemeChip Technology: HemeChip technology offers an original and innovative 
solution, leveraging a novel engineering approach, to point-of-care diagnosis of SCD. 
The basis of HemeChip technology lies in Hb electrophoresis, in which Hb types C, 
A2, S, F, and A0 have net negative charges in an alkaline solution. Differences in Hb 
mobilities allow separation to occur within the sieving medium, cellulose acetate 
paper. 

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There is no POC device for SCD or any other Hb disorder screening on the market. 
Currently available tests require skilled technicians in central labs. In Africa, HPLC 
costs up to $50 and takes 2-3 weeks to get the results. The National Institutes of 
Health in the United States has awarded a handful of innovation research grants in 
the past year to six small businesses to develop affordable POC diagnostic 
technologies for SCD (Correlia Bio., Rockland Immun., Daktari Diag., Silver Lake 
Res., Halcyon Biom., and Qoolabs). The vast majority of these companies rely on 
lateral flow immunoassays, which embody specific antibodies. Unlike the HemeChip 
technology, antibody based devices are specific to only a single disease, and would 
not work for different Hb disorders. Furthermore, the performance and reliability of 
lateral flow devices quickly degrade under uncontrolled environmental conditions in 
resource-limited countries.16 
HemeChip technology is a low-cost, point-of-care translation of the electrophoresis 
method that has been well established, readily accepted by clinicians, and widely 
applied in SCD diagnosis for well over 40 years. HemeChip was clinically tested and 
successfully benchmarked against available standard methods (i.e., HPLC, bench-top 
electrophoresis) using 82 blood samples from 27 patients at University Hospitals, 
Cleveland, USA. HemeChip offers a $2 screening test for SCD (and other Hb 
disorders), which takes 10 minutes to run. It is mobile and easy-to-use; it can be 
performed by anyone after a short (30 minute) training. The $2 HemeChip based 
newborn screening can be overlaid on existing successful (WHO, UNICEF data) 
primary vaccination programs in sub-Saharan Africa, as a time-for-screening. Primary 
customers would be the front-line health care workers in government-established 
immunization programs and pediatric clinics in sub-Saharan Africa. 
4. METHODOLOGY

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4.1  Study design 
This is a single site, cross-sectional study. 
4.2 Study site 
Study participants will be identified through the Community-Acquired Pneumonia and 
Invasive Bacteremia  Disease study (CAPIBD) currently enrolling at  three government 
hospitals in Kano, Nigeria to include Amino Kano Teaching Hospital, Murtala 
Mohammed Specialist Hospital and Hasiya Bayero Pediatric Hospital.  
Aminu Kano Teaching Hospital (AKTH) is one of the pioneer medical schools in 
northern Nigeria and provides tertiary referral service for several neighboring states. 
The 500 bed tertiary facility is located in the state of Kano and lies within the Sudan 
savannah belt. AKTH has a staff strength of 1,984 and serves as the teaching hospital 
for Bayero University Kano. The hospital provides health care for Kano and 5 
neighboring states, which has a combined population of over 25 million people. AKTH 
receives regular power supply from the public grid and has both generator and battery 
backups. Murtala Muhammed Specialist Hospital (MMSH) and Hasiya Bayero 
Children’s Hospital are affiliated government hospitals where faculty, residents and 
students from AKTH rotate to gain pediatric experience.  
Murtala Mohammad Specialist Hospital is one of the pioneer hospitals in Nigeria. 
Established in 1924, it is reputed to be the second largest hospital in West Africa. It is 
located in the central city of Kano State and as such, caters for a majority of the 
estimated 10 million people in the State. The hospital has a staff strength of 1,917 out 
of which, there are about 97 medical doctors and 415 nursing staff. The outpatient 
clinics cater for an average of 30,000 patients monthly. 
4.3 Subjects/study population 
Subjects eligible for this study include children age 6 weeks to 60 months  enrolled in 
CAPIBD from one of the three enrollment sites in Kano, Nigeria.  

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Inclusion/Exclusion criteria 
Inclusion criteria: 
Age 6 weeks to 60 months with one of the following true: 
1. fever or hypothermia (Temp ≥38 C or ≤36 C)  Plus one of the following
(prostration, excessive crying, poor feeding, altered consciousness, convulsion,
difficulty breathing, profuse vomiting, diarrhea)
2. Rapid breathing (0-2months>60 breaths/min, 3-12months >50 breaths/min, 13-
59 months > 40 breaths /min)
AND 
3. Provision of signed and dated written informed consent by parent or guardian
Exclusion criteria: 
1.
Parent of child chooses to opt out of the study after initial consent.
2.
Blood transfusion within 3 months of study enrollment.
3.
Presence of condition or abnormality that in the opinion of the investigator
would compromise the safety of the child or the quality of the data.
4.4 Sample size estimate 
Sample size is based on the known prevalence of SCD in Nigeria (SCD prevalence 
of 2.39% and a carrier rate of about 23%)19, using the following formula and a 95% 
confidence interval.17 
1. Specify clinically acceptable values for the width of 95% confidence interval
(CI), sensitivity (SN), specificity (SP), and the disease prevalence (P).
2. Calculate the number of patients with disease, defined as the sum of true
positive cases (TP) and false negative cases (FN) using:
2
2
2
/
)
1(
W
SN
SN
Z
FN
TP




3. Calculate the sample size required to obtain the desired sensitivity as:
P
FN
TP
N


1
4. Calculate the number of patients without disease, defined as the sum of true
negative cases (TN) and false positive cases (FP) using:

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2
2
2
/
)
1(
W
SP
SP
Z
FP
TN




5. Calculate the sample size required to obtain the desired specificity as:
P
FP
TN
N


2
Where Zα/2 is a statistical constant having a value of 1.96 for 95% CI. 
6. Select the required sample size as the greater of N1 and N2.
The calculations made for the HemeChip test sample size are summarized in 
Table 1 below: 
Prevalence estimate  
  P 
Width of the 95% CI: 10%  
 W 
Sensitivity expected: 98%  
  SN 
Specificity expected: 98%  
  SP 
Statistical constant, 1.96 for 95% CI 
  Zalpha 
Number with disease, True Positive + False Negative  
 TP+FN 
Sample size required for sensitivity  
 N1 
Number without disease, False Positive + True Negative  
 FP+TN 
Sample size required for specificity
    N2 
0.024 
0.10 
0.97 
0.97 
1.96 
11 
468 
11 
11 
FINAL SAMPLE SIZE (greater of N1 and N2) 
468 
Total maximum enrollment of 5,000 patients, age 6 weeks to 60 months
identified through CAPIBD.  

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Procedure 
The CAPIBD medical officer will introduce the study and ask if parent/caregiver 
is willing to participate. If yes, signed informed consent will be obtained and the 
subject assigned a unique identification number through CAPIBD. The clinical 
research assistant (CRA) assigned to the study will complete a questionnaire 
including demographic data and family information, and perform a heel or finger 
prick to obtain a blood sample for HemeChip and HPLC (page 12).  
HemeChip Test 
a. Finger-stick or heel-stick blood sample (20 µL) is mixed with deionized
water for red blood cell lysis and the mixture allowed to set for 3 minutes.
b. 65 µL of a buffer solution is used to wet the paper inside the HemeChip.
c. A disposable metal applicator is used to stamp 1 µL of the mixture onto the
paper strip inside the HemeChip through the sample application port.
d. 185 µL of the buffer solution is pipetted into two buffer chambers through
buffer loading inlets on the HemeChip.
e. The HemeChip is loaded into the reader and the power supply in the reader
turned on. The test runs for five minutes and diagnosis is obtained on a
computer connected to the reader.
f.
Data is stored on computer and results delivered by fax delivery and
secured email to a dedicated port for the attention of study PI.
g. Study CRA contacts caregivers of screen-positive children via phone and
all who screen positive will be referred to the local SCD clinic for follow up
care.
HPLC Test 
a. All blood samples collected via heel or finger prick on dot-blot paper will be
shipped to the IFAIN lab in Abuja on a monthly basis.

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b. HPLC confirmatory results will be obtained from the IFAIN lab on a monthly
basis.
c. Study CRA contacts caregivers of screen-positive babies via phone
following confirmatory results.
d. All subjects with abnormal HPLC results will be enrolled in the pediatric
sickle 
cell 
clinic, 
for 
parental 
education, 
penicillin 
prophylaxis,
pneumococcal 
vaccination, 
malaria 
prevention, 
fever 
and 
pain
management protocol, splenic palpation and contact with SCD team.
4.4 Data handling and quality assurance 
The PI will ensure the accuracy, completeness, and timeliness of the data recorded. 
Only the investigators and designated study personnel will have access to these data. 
Identified patients will be given a unique study number through CAPIBD and only the 
study number will be included in the dataset. Once a complete dataset has been 
gathered on all patients, the identifiers will be discarded, and only the de-identified 
data will be maintained. Study personnel will enter data from source documents 
corresponding to a subject’s visit into the protocol-specific electronic Case Report 
Form (eCRF). All data collected during the course of this study will be reviewed and 
verified for completeness and accuracy by the PI.  
The data will be entered into a validated database, which will allow safe and secure 
storage. After data have been entered into the study database, a system of 
computerized data validation checks will be implemented and applied to the database 
on a regular basis. Any changes to the study database will be documented. 
4.5  Statistical analysis 
Data will be analyzed and reported based on established methods in the literature.18 
Statistical significance will be set at 95% confidence level for all tests (p<0.05). 
Receiver-operating curves will be utilized to assess sensitivity and specificity of 

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HemeChip in comparison to HPLC as the standard test. Sensitivity will be calculated 
as # true positives / (# true positives + # false negatives) and specificity will be 
calculated as # true negatives / (# true negatives + # false positives). Positive 
predictive value (PPV) will be calculated as # true positives / (# true positives + # false 
positives) and negative predictive value (NPV) will be calculated as # true negatives / 
(# true negatives + # false negatives). 
5 Dissemination of results 
Study results will be disseminated at a clinical meeting in the Department of Child 
Health at Case Western Reserve University, published in peer-reviewed scientific 
journals and presented at relevant scientific conferences.  
6 ETHICAL ISSUES 
6.4 Study conduct 
The study will be performed in accordance with ethical principles that have their origin 
in the Declaration of Helsinki and are consistent with the International Conference on 
Harmonization (ICH)/Good Clinical Practice (GCP).  
Informed consent 
All study participants must have a legal representative that is in competent mental 
condition to provide written, informed consent on behalf of the study subject before 
entering the study. A copy of the signed informed consent form will be given to the 
parent or legal guardian.   Each subject, parent or legal guardian will be notified that 
they are free to withdraw from the study at any time.    
6.5  IRB of record 
There will be no research activity performed or data collection at UNMC. All research 
activity and data collection will be performed at the Nigeria site. The CWRU team will 
take responsibility for data collection, storage, submitting continuing reviews and 

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amendments for the study. CWRU team will also give the approved documents to 
UNMC in a timely manner and make sure to keep track of everything that occurs at that 
site.  
University of Nebraska Medical Center (UNMC) has developed several microbiology 
diagnostic laboratories for invasive bacterial infections in Nigeria children. UNMC 
supports the International Foundation Against Infectious Disease (IFAIN),a registered 
non-profit in Nigeria, which manages local research activities. The Co-I from 
UNMC, (Stephen Obaro) is founding member and Trustee of IFAIN and the PI on 
several rants currently in execution by UNMC through IFAIN in Nigeria. Some of the 
services IFAIN provides include microbiology and molecular diagnostic services, such 
as sickle cell disease screening through HPLC. UNMC also has a strong network with 
multiple researchers across Africa who work with hemoglobinopathies and vaccine 
preventable infections. UNMC provides essential expertise and support to fulfill the 
activities for our proposal.  
6.6 Safety 
The study poses minimal risk to participants. There will be the minor discomfort of a 
heel (or finger) prick. Bruising at the site of skin puncture may occur. For 
parents/caregivers, there is a small, time inconvenience for administration of the study 
questionnaire. 
Timeline/Work schedule 
Timeline: 

IRB approval: 2 months (FEB/MAR 2017)

Recruitment and training of study staff: 1 month (MAR 2017)

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
Recruitment: 3 months (APR 2017 to JULY 2017)

Data entry, cleaning and analysis: APR 2017 to AUG 2017

Write up and dissemination: AUG 2017 to OCT 2017
International Collaborators: 
Umut A. Gurkan, PhD 
Assistant Professor 
Case Biomanufacturing and Microfabrication Laboratory 
Mechanical and Aerospace Engineering Department 
Biomedical Engineering Department 
Case Western Reserve University (CWRU) 
Office: Glennan 616B,  10900 Euclid Ave., Cleveland, OH 44106 
 Phone: +1 (216) 368-6447 
 Fax: +1 (216) 368-3007 
 Email: umut@case.edu; Web: http://www.case-bml.net 
Stephen K. Obaro, M.D., Ph.D. 
Professor, Division of Pediatric Infectious Diseases 
University of Nebraska Medical Center 
982162 Nebraska Medical Center  
Omaha, Nebraska 68198-2162 
stephen.obaro@unmc.edu  
REFERENCES
1. Aygun B, Odame I. A global perspective on sickle cell disease. Pediatr Blood
Cancer. 2012;59(2):386-390.
2. Mulumba LL, Wilson L. "Sickle cell disease among children in Africa: An
integrative literature review and global recommendations". International Journal
of Africa Nursing Sciences, 3: p. 56-64, 2015.

 Page 16 of 17 
Version date: 1.4; 17 September 2018 
3. Manwani D, Frenette P. Vaso-occlusion in sickle cell disease: pathophysiology
and novel targeted therapies. Blood. 2013;122(24):3892-3898.
4. Jain D, Lothe A, Colah R. Sickle cell disease: current challenges. J Hematol
Thrombo Dis. 2015;3:224. doi:10.4172/2329-8790.1000224.
5. Piel F, Hay S, Gupta S, Weatherall D, Williams T. Global burden of sickle cell
anaemia in children under five, 2010–2050: modelling based on demographics,
excess mortality, and interventions. PLoS Med. 2013;10(7):e1001484.
6. Odievre MH, Verger E, Silva-Pinto AC, Elion J. Pathophysiological insights in
sickle cell disease. Indian J Med Res. 2011;134:532-537.
7. Kanter J, Kruse-Jarres R. Management of sickle cell disease from childhood
through adulthood. Blood Rev. 2013;27(6):279-287.
8. Vichinsky E, Hurst D, Earles A, Kleman K, Lubin B. Newborn screening for sickle
cell disease: effect on mortality. Pediatrics. 1988;81(6):749-55.
9. Frempong T, Pearson HA. Newborn screening coupled with comprehensive
follow-up reduced early mortality of sickle cell disease in Connecticut. Conn Med.
2007;71(1):9-12.
10. Odame I. Developing a global agenda for sickle cell disease. Am J Prev Med.
2010;38(4):S571-S575. 
11. Wethers DL. Sickle cell disease in childhood: Part II. Diagnosis and treatment of
major complications and recent advances in treatment. Am Fam
Physician.2000;62(5):1013-1020.
12. Bain BJ. Haemoglobinopathy Diagnosis. 2nd ed. Malden, MA, USA: Blackwell;
2006. 
13. Bain BJ, Wild B, Stephens A, Phelan L. Variant haemoglobins: a guide to
identification. Oxford, UK: Wiley-Blackwell; 2011. 260 p. 
14. Clark BE, Thein SL. Molecular diagnosis of haemoglobin disorders. Clinical Lab
Haematol. 2004;26(3):159-176. 
15. Ashley-Koch A, Yang Q, Olney RS. Sickle hemoglobin (HbS) allele and sickle

 Page 17 of 17 
Version date: 1.4; 17 September 2018 
cell disease: a HuGE review. Am J Epidemiol. 2000;151(9):839-845. 
16. Chiodini PL, Bowers K, Jorgensen P, Barnwell JW, Grady KK, Luchavez J, et al.
The heat stability of plasmodium lactate dehydrogenase-based and histidine-rich 
protein 2-based malaria rapid diagnostic tests. Trans Roy Soc Trop Medicine 
Hyg. 2007;101(4):331-337. 
17. Buderer NM. Statistical Methodology: I. Incorporating the prevalence of disease
into the sample size calculation for sensitivity and specificity. Acad Emerg Med.
1996;3(9):895-900.
18. Parikh R, Mathai A, Parikh S, Chandra Sekhar G, Thomas R. Understanding and
using sensitivity, specificity and predictive values. Indian J Ophthalmol.
2008;56(1):45-50.
19. Ademola Samson Adewoyin, “Management of Sickle Cell Disease: A Review for
Physician Education in Nigeria (Sub-Saharan Africa),” Anemia, vol. 2015, Article
ID 791498, 21 pages, 2015