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eNeurologicalSci

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Validation of two parent-reported autism spectrum disorders screening tools
M-CHAT-R and SCQ in Bamako, Mali

Modibo Sangarea,f,⁎, Hamza B. Toureb, Amadou Tourec, Adama Karembea, Housseini Doloa,
Yaya I. Coulibalya, Modibo Kouyatea, Kadiatou Traored, Seidina A. Diakitéb,f,
Souleymane Coulibalyd, Arouna Togorad, Cheick Oumar Guintoe, Gordon A. Awandaref,
Seydou Doumbiaa, Mahamadou Diakiteb,f, Daniel H. Geschwindg

a Faculty of Medicine and Odontostomatology, University of Sciences, Techniques and Technology of Bamako, Bamako, Mali
b Faculty of Pharmacy, University of Sciences, Techniques and Technology of Bamako, Bamako, Mali
c Department of Pediatrics, University Hospital Gabriel Toure, Bamako, Mali
d Psychiatry Department, University Hospital Point G, Bamako, Mali
eNeurology Department, University Hospital Point G, Bamako, Mali
fWest African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
g Department of Neurology and Psychiatry, Center for Autism Research and Treatment, UCLA, Los Angeles, United States

A R T I C L E I N F O

Keywords:
M-CHAT-R
SCQ
NPV
PPV
Mali

A B S T R A C T

Background: Early screening is crucial for early autism spectrum disorders (ASD) diagnosis and intervention.
ASD screening tools have mostly been constructed based on the Western cultural context. We hypothesized that
their use in Mali may require a prior validation.
Objective: To validate the modified checklist for autism in toddlers-Revised (M-CHAT-R) and the social com-
munication questionnaire (SCQ) in the Malian sociocultural context for ASD screening.
Study design: We administered M-CHAT-R and SCQ in 947 toddlers aged 16–30months old at the district and
community health centers in Bamako and 120 patients (60 autistic and 60 age and sex matched controls) aged
≥4 years old at the psychiatry department in Bamako. Toddlers at moderate to high risk of ASD underwent M-
CHAT-R/F and clinical evaluation by an ASD multidisciplinary team. M-CHAT-R and SCQ were evaluated for
cultural appropriateness by Malian anthropologists. The sensitivity, specificity, PPV, NPV were determined for
both M-CHAT-R and SCQ. Health professionals have been trained during ASD seminary on how to use M-CHAT-R
and SCQ for ASD screening in Bamako.
Results: We found for the M-CHAT-R a sensitivity of 50%, a specificity of 100%, a PPV of 100% and a NPV of
87%. The SCQ had a sensitivity of 71%, a specificity of 72%, a PPV of 73% and a NPV of 70%. We have found
four out of 20 items on the M-CHAT-R that were culturally inappropriate in the Malian context.
Discussion: M-CHAT-R and SCQ can be used for early autism screening in Mali. In the future, we plan to train a
descent number of Malian physicians in chief and pediatricians at the district hospitals across the country to
integrate the early ASD screening into the national health system.
Conclusion: M-CHAT-R has a perfect specificity and SCQ a fair diagnostic accuracy for ASD in Mali.

https://doi.org/10.1016/j.ensci.2019.100188
Received 7 March 2019; Accepted 9 March 2019

Abbreviations: AMALDEME, Malian association for mental deficiencies; ASD, Autism spectrum disorders; AUC, Area under the Curve; CHU, University hospital
centers; CSCOM, Community health centers; CSRef, District health centers; DNS, National direction of health; DRS, Regional direction of health; DSM-V, Diagnostic
and Statistical Manual of Mental Disorders; FAPH, Faculty of Pharmacy; FMOS, Faculty of medicine and odonto-stomatology; ICD-10, International Statistical
Classification of Diseases and Related Health Problems-10; LR+, Positive likelihood; LR-, Negative likelihood; M-CHAT-R, Modified checklist for autism in toddlers-
Revised; M-CHAT-R/F, Modified checklist for autism in toddlers-Revised/Follow up; NPV, Negative predictive value; SCQ, Social communication questionnaire; PPV,
Positive predictive value; USTTB, University of Sciences, Techniques and Technologies of Bamako

⁎ Corresponding author at: University of Ghana, Faculty of Medicine and Odonto-Stomatology, University of Sciences, Techniques and Technologies of Bamako, BP:
1805, Bamako, Mali.

E-mail addresses: mouadib@gwu.edu (M. Sangare), sdiakite@icermali.org (H.B. Toure), gawandare@ug.edu.gh (G.A. Awandare),
dhg@mednet.ucla.edu (D.H. Geschwind).

eNeurologicalSci 15 (2019) 100188

Available online 11 March 2019
2405-6502/ © 2019 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license
(http://creativecommons.org/licenses/BY-NC-ND/4.0/).

T

1. Introduction

The modified checklist for autism in toddlers-Revised (M-CHAT-R)
and the social communication questionnaire (SCQ) are parent report-
based autism spectrum disorder (ASD) screening tools developed and
widely used in the Western countries. The M-CHAT-R is used to screen
toddlers aged 16–30months old, whereas the SCQ is for autistic in-
dividuals aged ≥4 years old. The use of such ASD screening tools in
Africa requires prior validation in the local sociocultural context.

In Mali, ASD is not only stigmatized, but also not well recognized by
most people, including health professionals. ASD is more common in
Mali than previously expected. Our preliminary data showed 1 in 27
neuropsychiatric outpatients (4.5% or 105/2343) at the psychiatry
department of the University hospital Point G was autistic. Parents and
families more often don't seek diagnosis and care for their autistic
children. Autistic children with epilepsy as comorbidity aggressive be-
havior are more likely to be visited by a physician or a health profes-
sional in late childhood (unpublished data). The grandmothers of tod-
dlers at risk of ASD are more likely to grow suspicious about early ASD
symptoms in their families. Most health professionals including pedia-
tricians were unaware of ASD before our ASD awareness activities in
Bamako, the capital city of Mali. ASD was not taught at the medical
until 2014 when our ASD research first started at the faculty of medi-
cine and odonto-stomatology (FMOS) in Bamako. Training health pro-
fessionals at the community health centers in the use of M-CHAT-R and
SCQ in rural and urban Mali is crucial in raising ASD awareness and
facilitating the recruitment of ASD families into our ASD research
protocol. Especially in the context of how few child psychiatrists or
neurologists there are in all of Mali and Africa for that matter. M-CHAT-
R and SCQ would fill the immense void in early ASD screening in Mali.

We hypothesized that M-CHAT-R and SCQ could be successfully
validated in the Malian population. In this study, we aimed to validate
M-CHAT-R and SCQ lifetime in a general population based survey at
district health centers (CSRef) and community health centers (CSCOM)
in Bamako.

2. Materials and methods

2.1. Description of the health system in Mali

The Malian health system is organized into three tiers in Bamako
from the bottom/local to the top in terms of intensity: the community
health centers, CSCom (n= 57); the district health centers, CSRef
(n=6), one in each of the six administrative communes, and the
University hospital centers, CHU (n= 6). Private health structures exist
at each level. The referrals are normally done from the bottom
(CSCOM) to the top (CHU). Public and private health structures are
under the direct authority of the regional direction of health (DRS) and
the National direction of health (DNS). The ministry of health and
public hygiene is the highest health authority in the country.

2.2. Generation of preliminary data

In 2014, we reviewed 12,000 medical charts of children aged
14 years old and younger from a decade of medical practice (outpatient
visits) at the psychiatry department of the University hospital Point G
and at the private clinic Kaidara in Bamako, Mali. The diagnostic of
ASD was based on the Diagnostic and Statistical Manual of Mental
Disorders (DSM-V) and the International Statistical Classification of
Diseases and Related Health Problems-10 (ICD-10).

3. M-CHAT-R/F administration and scoring

3.1. M-CHAT-R administration

Our ASD research protocol, consent and assent forms, and

questionnaires have been approved by the IRB at the faculty of medi-
cine and odonto-stomatology (FMOS)/Faculty of Pharmacy (FAPH) at
the University of Sciences, Techniques and Technologies of Bamako
(USTTB). Fourteen surveyers (12 health professionals and 2 non-health
professionals, graduates from the school of public administration in
Bamako) were trained during a 1-day seminary on ASD, M-CHAT-R
administration and the study design. After the approval of the regional
direction of health (DRS) in Bamako, we paired up the health profes-
sional surveyers and each pair was assigned one of six district health
centers (ex-CSRef) and its two most frequented community health
centers (CSCOM). The two non-health professionals worked with each
pair of surveyors to administer in parallel the study questionnaire to the
same toddlers (100 in total). The 2-page study questionnaire consisted
of the French version of the M-CHAT-R and another questionnaire to
collect sociodemographic and risk factors data for the toddlers aged
16–30months old and personal information of his/her parents. At the
CSCOM level, community consents were obtained with the traditional
leaders and mayors; local guides were used for community engagement.
Each study participant received compensation. The survey lasted five
weeks (three at the CSRef level and two at the CSCOM level).

3.2. M-CHAT-R scoring

Each item in the M-CHAT-R requires a dichotomous “yes”/“no”
response, and each scored item receives 1 point for presence of the
abnormal behavior and 0 points for its absence or the presence normal
behavior. Yes means abnormal behavior in all the items except Items 2,
5 and 12 for which No means abnormal behavior. The ASD risk was
estimated as followed: score= 0–2 (low risk), score= 3–7 (moderate
risk) and score= 8–20 (high risk).

3.3. M-CHAT-R/F administration

The parents or guardians of toddlers at moderate to high ASD risk
were contacted and invited for the M-CHAT-R/F and clinical evaluation
by our multidisciplinary ASD research team at the University hospital
Point G. The discussion during the clinical evaluation was based on the
presence or absence of early ASD red flag signs and symptoms by age
one year old. Each study participant was compensated for the partici-
pation and reimbursed for transportation.

4. SCQ administration and scoring

A medical student, as part of his MD thesis, and a junior psychiatrist,
both used the SCQ lifetime version to screen 60 patients aged
4–20 years old diagnosed with ASD per the DSMV criteria during the
weekly ASD clinic at the psychiatry department of the University hos-
pital Point G and 60 age and sex matched controls (26 epilepsy cases
and 34 other neuropsychiatric disorders including mental retardation,
acute psychosis, cerebral palsy, etc.…) from Point G and the mental
health care center for the Malian association for mental deficiencies
(AMALDEME) in Bamako. In Point G, informed consent was obtained
from the accompanying adults and patients who were 18 years old and
older. Younger patients if not emancipated signed the assent forms.
Compensation was given to each study participant. At the AMALDEME,
after the approval of the director of the center, three research nurses
who are the daily caregivers and guardians of the patients consented for
the study and provided information on patients. Nurses were compen-
sated individually, but the IRB approved rate for compensation was
added up for the total number of study participants in the center. The
equivalent in food (powder milk, sugar, snake, tooth paste and tooth-
brush) was handed to the director for the participants. The study par-
ticipant recruitment lasted six months in Point G and one month at the
AMALDEME. The filled SCQ questionnaires were reviewed and scored
by the research team.

Each item in the SCQ requires a dichotomous “yes”/“no” response,

M. Sangare, et al. eNeurologicalSci 15 (2019) 100188

2

and each scored item receives 1 point for abnormal behavior and 0
points for its absence or normal behavior. The first item—“Is she/he
now able to talk using short phrases or sentences?”—is not scored, but
rather determines whether six items for abnormal language are scored.
Only “verbal” children (i.e., children with a “yes” response to the first
question) are assigned the six items relating to abnormal language
while “non-verbal” children (i.e., children with a “no” response to the
first question) are not resulting in a 6-point total score difference be-
tween the two groups. The ASD risk was based on the following cutoff:
score < 15 out of 40 (no risk) and score > 15 (at risk).

5. Anthropologic evaluation of M-CHAT-R and SCQ

Each of the 20 items on the M-CHAT-R and 40 items on the SCQ
were evaluated for their appropriateness in the Malian sociocultural
context. In other words, the question in each item of the M-CHAT-R and
SCQ was evaluated with the following two concerns: (i) is the question
as formulated easy to understand by mothers mostly illiterate? (ii) Are
the objects (examples: airplane, vacuum cleaner, etc.…) or scenarios
(example: mimicking feeding a doll) in the question known or com-
monly used by most Malians? When inappropriate, a proposition was
made on how to rephrase the question in the item either by keeping its
key words or replacing some with equivalent words (example: noise
produced by a pestle in a mortar instead of that of a vacuum cleaner).
Our evaluation was based on the vast majority of Malians seen at the
CSCOM level meaning mostly uneducated and poor. The minority of
well-educated and wealthy Malians leading a Western lifestyle were not
taken into account since they are treated in ether private clinics or
University hospitals or even abroad.

6. ASD awareness seminary

A 1-day ASD awareness seminary has been developed in the fol-
lowing format: (i) oral presentation on the general information on ASD
followed discussion on the early ASD symptoms in toddlers (ii) testi-
monials of four Malian ASD families (iv) review of the items on M-
CHAT-R and SCQ (v) attendees practice M-CHAT-R and SCQ on the
available ASD families (vi) each attendee received a dozen of copies of
M-CHAT-R and SCQ for autism screening at their respective health
centers and give ideas on how early ASD screening could be im-
plemented into the Malian health system.

7. Sample size

In total, 947 questionnaires were used for the M-CHAT-R among
which only 17 out of 89 eligible took part to the M-CHAT-R/F and
clinical evaluation. For the SCQ, the sample size was set at 120 study
participants aged 4–20 years old (60 autistic and 60 age and sex mat-
ched controls with neuropsychiatric disorders other than ASD) based on
feasibility. We calculated for both the M-CHAT-R and the SCQ the
sensitivity, specificity, positive predictive value (PPV), negative pre-
dictive value (NPV), positive likelihood (LR+) and negative likelihood
(LR-), Area under the Curve (AUC) and the Youden's J.

8. Working definitions

8.1. Cutoff

The M-CHAT-R cutoff values were 1–2 for low risk, 3–7 for mod-
erate risk and 8–20 for high risk. Only a score≥ 8 was eligible for the
M-CHAT-R/F and clinical evaluation. The SCQ cutoff value was 15 as
suggested in the manual of SCQ, a total SCQ score > 15 meant positive
or < 15 negative ASD diagnosis for each study participant [1].

8.2. Sensitivity or true positive rate

The proportion of toddlers or patients with ASD who are correctly
identified as having ASD or at ASD risk. Specificity or true negative
rate: the proportion of toddlers aged 16–30months old or patients aged
4–20 years old without ASD who are correctly identified as not having
ASD. Interpretation of the values: 1.0= perfect; 0.9–1.0= very good;
0.8–0.9= good; 0.7–.0.8= fair;< 0.7= poor [2].

8.3. Youden's J

It was calculated using the formula: Sensitivity+ Specificity – 1 as
an indicator to establish the optimal cutoff point. It gives equal weight
to sensitivity and specificity. Values from +1 (indicates a perfect
measure with neither false positives nor false negatives) to −1 (in-
dicates a perfect inverse measure). A value of 0 indicates that the
measure has no value [3].

8.4. Area under the ROC curve

A measure of how well the SCQ Total Score can distinguish between
the presence of an ASD diagnosis and the absence of an ASD diagnosis.
AUC varies between 0 and 1 (in normalized units), where the diagnostic
accuracy is perfect (AUC=1.0); very good (AUC is between 0.9 and
1.0); good (AUC is between 0.8 and 0.9); fair (AUC is between 0.7 and
0.8); poor (AUC is between 0.6 and 0.7); very poor (AUC is between 0.5
and 0.6); and non-discriminating (AUC=0.5) [4].

8.5. Negative predictive value (NPV)

NPV is the probability of a person who receives a negative test result
actually does not have the disease. Positive predictive value (PPV) is the
probability of a person who receives a positive test result actually has
the disease [5].

Likelihood ratios (LR), sensitivity and specificity data have been
used to calculate the Likelihood ratio for positive test results (LR+) and
Likelihood ratio for negative test results LR-. For both M-CHAT-R and
SCQ, LR+ was calculated using the formula: sensitivity/(1-specificity)
as an indicator for ruling in the diagnosis or risk of ASD where higher is
better. Good diagnostic tests have LR+ > 10. LR− was calculated
using the formula: (1-sensitivity)/specificity as an indicator for ruling
out the diagnosis or risk of ASD where lower is better. Good diagnostic
tests have LR- < 0.1 [1].

8.6. Ethical considerations

Study participation was voluntarily. Compensation was given to the
study participants. No personal identifier, but a code was used in either
questionnaire. The key to the code was written on a spreadsheet and
stored in an excel database accessible only to the medical student,
epidemiologist and the principal investigator. The questionnaires were
stored in a locked cabinet at the FMOS, USTTB. Study participants
suffering from epilepsy received free antiepileptic medications (val-
proid acid and carbamazepine).

9. Results

From our preliminary data (Table 1), the diagnosis of ASD may be
relatively late in the childhood in Mali based on the age of first medical
visit (7.64 ± 3.85 years) of autistic children in Bamako. All the qua-
lified health professionals for ASD diagnosis are in Bamako, the capital
city. The further away from Bamako the scarcer the health services
implying an even later ASD diagnosis age in rural Mali. In addition,
only 11.4% (n=105) of autistic children were schooled in public
education where teachers are unaware of ASD. The annual new patient
rate of 7 and the hospital frequency of 4.5% (1 in 27) are

M. Sangare, et al. eNeurologicalSci 15 (2019) 100188

3

underestimating the number of ASD cases in Bamako. Finally, the rate
of first degree consanguinity of 13.9% and the history of psychosis on
maternal and paternal families in 6.15–7.21% (Table 1) highlighted the
potential for molecular ASD genetic research. Key to early ASD
screening and diagnosis in the Malian context relies on the easy-to-use
parent-reported ASD screening tools such as M-CHAT-R and SCQ.

10. Discussion

10.1. Interpretation and significance of the preliminary data for ASD
research in Mali with an emphasis on late ASD diagnosis

We found an ASD hospital frequency of 4.5%. Due to stigma sur-
rounding ASD, only few among many other parents seek care at the
hospital or private medical clinic for their autistic children. ASD is still
thought to be resulting from witchcraft or parental misdeed or sin.
Traditional healers and hunters are more likely to be consulted to treat
autistic children in rural even urban Mali. Perceptions on ASD and its
treatment options widely vary across cultures [6]. The peak of 22 ASD
patients in 2012 was due to the effect of the creation of the association
of autistic families affiliated to the pediatrics department of the Uni-
versity hospital Gabriel Toure.

10.2. Study limitations (sample size, age ranges, rural study site)

The age ranges for both M-CHAT-R and SCQ were set at
16–30months old and≥ 4 years old, respectively. The choice of these
two ASD screening tools will obviously leave children between
30months old and 4 years old unscreened. There is so much work to be
done in ASD screening and diagnosis in most African countries [7] that
we had to start somewhere in Mali. This study was limited to the eth-
nically diverse and mixed population in Bamako therefore our results
may not necessarily be extendable to some rural areas.

10.3. Anthropologic evaluation of the M-CHAT-R and SCQ

From one country to another or even between different ethnic
groups in same country, cultural differences may greatly influence on
how ASD is perceived and cared for worldwide [8]. We therefore had
the M-CHAT-R and SCQ reviewed by anthropologists at the FMOS in
Bamako for cultural appropriateness. While SCQ revealed no proble-
matic item, four items (3, 4, 6 and 12) were inappropriate in the Malian
sociocultural context. Coincidentally, those items were the only ones to
register the highest failed response rates (Table 2). For instance, asking
a question of the noise from a vacuum cleaner may mean nothing to
most of the surveyed mothers who might not have heard of such thing
before. Instead of a vacuum cleaner, they used the traditional wipers on

a daily basis.

10.4. Discuss the significance of the validation especially 100% specificity
of M-CHAT-R and 73% PPV of SCQ; discriminative capacity in ASD versus
ASD+ epilepsy

From our M-CHAT-R and SCQ validation data (Table 3), the sensi-
tivity of M-CHAT-R was as low as 50% with a specificity of 100%. With
limited ASD research funds per the 10/90 gap along the lack qualified
human resources in Africa [9] as well as the stigma surrounding ASD in
Mali, we prefer a screening that may be less sensitive, but very specific.
We don't want to label a child autistic when s/he is not. The PPV for
SCQ was 73% with a fair diagnostic accuracy (AUC=0.70) which
highlighted the need for a more accurate additional diagnostic tool not
solely based on parental reports. Autism diagnostic observation sche-
dule-2 (ADOS-2) will be the ideal ASD diagnostic aid tool to fill this gap.

Epilepsy is a frequent co-morbidity of ASD [10]. In our cohort, SCQ
picked up about 1 in 5 ASD with epilepsy when the cutoff is at 15
(Table 4). Should the cutoff be lower in this specific patient population
is worth of wonder, but it is obvious that epileptic crisis in which the
child falls down unconscious, bites his/her tongue, leaks urine and have
traumatism from the recurrent falls draw much more the attention of
their parents than autistic symptoms.

10.5. Training of health professionals across in Bamako, Mali

The use of M-CHAT-R and SCQ for ASD screening has been part of
our ASD awareness and research plan. After the validation of M-CHAT-
R and SCQ, we worked with the regional direction of health (DRS) to
train in ASD screening using M-CHAT-R and SCQ during a 1-day ASD
seminary the physician in chief and the pediatrician at all the six dis-
trict health centers (DRS) in Bamako. Work is underway to train in
using M-CHAT-R and SCQ for ASD screening 180 technical directors of
the centers (DTC) from all the community health centers (CSCOM) in
Bamako. Our ultimate goal is to establish a referral system using a
stepped care model in which toddlers aged 16–30months old and au-
tistic individuals aged ≥4 years old will be subsequently screened at
the CSCOM and CSRef levels before those at risk are referred to our ASD
research team at the FMOS in Bamako.

11. Conclusion

M-CHAT-R has a perfect specificity and SCQ a fair diagnostic ac-
curacy for ASD in Mali. In the future, physicians including the DTC will
be initiated into the use of M-CHAT-R/F and SCQ. In addition, other
ASD screening tools in toddlers [11] and ADOS-2 will be validated and
used to supplement M-CHAT-R/F and SCQ. Finally, these M-CHAT-R/F
and SCQ validation data will be relevant and useful in many other West
African countries.

Table 1
Study population description in the preliminary data and M-CHAT-R survey.

Preliminary data from the medical chart
review

Values

Sex ratio 1.5
Age range 3–14 years old
Average age at the first outpatient visit 7.64 ± 3.85 years old
Schooling rate of autistic children 11.4% (n=105)
Average number of new patients per year from

2000 to 2014
7 (peak of 22 in 2012)

ASD hospital frequency 4.5% (n=2343)
First degree consanguinity rate (%) with 95%

CI
13.19% IC95%= [11.86–14.6]

Family history of psychosis in paternal side 7.21% IC95% = [6.22–8.31]
Family history of psychosis in maternal side 6.15% IC95% = [5.23–7.17]
M-CHAT-R survey Values
Sex ratio 1.08
Age range 16–30months old
Rate of non-educated mothers 70% (n=947)

Table 2
Anthropologic evaluation of appropriateness in the Malian sociocultural con-
text of the items on the M-CHAT-R.

Item# on the
M-CHAT-R

Appropriateness in the Malian
sociocultural context

Yes or No
response

Frequency (%)
N=82**

3 No No 20 (24.4%)
4 No No 20 (24.4%)
6 No No 40 (48.8%)
12 No No 37 (45.1%)

*Items on M-CHAT-R were reviewed for the 82 of the 90 toddlers eligible for
follow up and clinical evaluation. The frequency of failed responses and cor-
responding percentages were determined.
Note: All the 40 items on the SCQ were labeled appropriate in the Malian so-
ciocultural context.

M. Sangare, et al. eNeurologicalSci 15 (2019) 100188

4

Funding statement

“Dr. Modibo Sangare, MD, PhD was supported by a postdoctoral
fellowship from a DELTAS Africa grant “DEL-15-007: Awandare” to
“Professor Gordon Awandare”. The DELTAS Africa Initiative is an in-
dependent funding scheme of the African Academy of Sciences (AAS)’s
Alliance for Accelerating Excellence in Science in Africa (AESA) and
supported by the New Partnership for Africa’s Development Planning
and Coordinating Agency (NEPAD Agency) with funding from the
Wellcome Trust (107755/Z/15/Z: Awandare) and the UK government.
The views expressed in this publication are those of the author(s) and
not necessarily those of AAS, NEPAD Agency, Wellcome Trust or the UK
government.” Dr. Modibo Sangare was also a grantee of the University
of Sciences, Techniques and Technologies of Bamako (USTTB), Ministry
of Innovation and Scientific Research of Mali.

Acknowledgements

We would like to acknowledge Dr. Andrey Thurm at the National

Institute of Mental Health (NIMH), NIH, US, Professor Petrus De vries at
the University of Cape Town in South Africa currently in sabbatical in
Australia, Professor Kenneth H Fischbeck at the Neurogenetics Branch
(NGB), NINDS, NIH, US for their useful comments and/or contribution
to the study design. We thank the technical directors of the community
health centers (CSCom) in Bamako for collaborating during the survey.

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Table 3
Validation data of M-CHAT-R and SCQ in Bamako, Mali.

Characteristics M-CHAT-R SCQ lifetime

Sex ratio (male/female) 1.08 1.6
Median age with extremes 24months old with the extremes of 16–30months old 10 years old with the extremes of 4 and 20 years old
Sample selection Communitybased-screening Health facility-based screening
ASD risk estimation low risk (n=857)

moderate risk (n= 83)
high risk (n= 7)

no risk (16 autistic patients and 42 controls) at risk (44 autistic patients and 18
controls)

Sample size and characteristics M-CHAT-R (n= 947)
M-CHAT-R/F (n= 90)
Clinical evaluation (n=17)

N=120 (60 autistic patients⁎ and 60 age and sex matched controls)

Sensitivity 50%(2/4) IC95% [0.08–0.91] 71% (44/60) IC95% [0.61–0.82]
Specificity 100%(13/13) IC95% [0.77–1] 72% (42/60) IC95% [0.57–0.80]
Area Under the Curve (AUC) Not applicable 0.70
Positive predictive value 100%(2/2) IC95% [0.17–1] 70%(44/62) IC95% [0.59–0.81]
Negative predictive value 87%(13/15) IC95% [0.62–0.97] 72%(42/58) IC95% [0.60–0.82]
Positive likelihood (LR+) Not applicable 2.5
Negativelikelihood (LR-) 0.5 0.01
Youden's J 0.50 0.49

⁎ Among the 60 autistic patients, 26 (43.3%) had clinically diagnosed epilepsy and 43 (71.7%) were nonverbal.

Table 4
Discriminative capacity of the SCQ lifetime in diagnosing ASD in the presence
or absence of epilepsy as a co-morbidity.

ASD screening tool Score Autistic Non-Autistic Total

SCQ >15 44 (73.3%) nnn(0%) 44 (73.3%)
< 15 0(0%) 16 (26.7%) 16 (26.7%)
Total 44 (73.3%) 16 (26.7%) 60 (100%)
Score Epileptic Non-Epileptic Total

SCQ >15 5 (19.2%) 0(0%) 5 (19.2%)
< 15 0(0%) 21 (80.8%) 21 (80.8%)
Total 5 (19.2%) 21 (80.8%) 26 (100%)

M. Sangare, et al. eNeurologicalSci 15 (2019) 100188

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