Rlptk Screening Results for Children 18 - 30 Months Old Using M-Chat Checklist

Screening sample n = 42,551

Screening (M-CHAT) n = 40,243

Positive n = 514

Negative n = 39,729

Invite (100%) 514 positive children

Missing form 19

Invite 1028 negative children

Missing form 241

495 children diagnosed

Diagnosed 787 children

302 RLPTK

193 No

RLPTK

03 RLPTK

784 no

RLPTK

Diagnostic Examination (DMS-IV)

Figure 3. 1. Screening and diagnosis process for RLPTK

3.2.1. Results of screening for autism spectrum disorder in children 18-30 months old using the M-CHAT checklist

Table 3.6: Some information about screening activities using the M-CHAT checklist

Characteristic

Number of children (n)	Rate (%)
People perform	Medical staff	25,580	63.6
People perform	Village Health/DS Collaborator	14,663	36.4
Qualification of the performer	Doctor	3,294	8.2
	Nursing	6,024	15.0
	Midwife	6,074	15.1
	Doctor	11,261	28.0
	First aid	13,590	33.8
Respondent	Parents	33,347	82.8
	Grandparents	6.234	15.5
	Other (aunt, uncle, housekeeper)	662	1.7

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The majority of people who screened children using M-CHAT were health station staff (63.6%), the rest were village health workers or population collaborators who screened (36.4%). The professional qualifications of those who screened children included 33.8% primary health care workers, 28% medical doctors, 15% midwives, 15% nurses/medical staff and 8% doctors. The majority of interviewees were fathers or mothers of children, accounting for nearly 83%.

Table 3.7: Screening results using M-CHAT checklist

M-CHAT Score

Number of children (n)	Rate (%)
Positive	514	1.3
Negative	39,729	98.7
Total	40,243	100.0

The study successfully screened children for the risk of ASD using M-CHAT.

40,243 children. Results showed that 1.3% of children tested positive for M-CHAT.

3.2.2. Diagnostic results of RLPTK in children 18-30 months old using DSM-IV

Table 3.8: Autism diagnosis results using DSM-IV

Autism

Number of children (n)	Rate (%)
Autism	305	0.76
Not Autistic	39,938	99.24
Total	40,243	100.00

The prevalence of RLPTK in children aged 18-30 months in 7 provinces/cities through screening with M-CHAT and diagnosis with DSM-IV is 0.75%.

Table 3.9: Analysis of abnormal signs of children with autism spectrum disorder through M-CHAT

Sentence

Child signs:	Children with autism spectrum disorder (n=305)
Child signs:	Number of children (n)	Rate (%)
1	Don't like to swing or bounce on laps	70	23.0
2	Not interested in other children	203	66.6
3	Does not like climbing on objects	62	20.3
4	Don't like to play peek-a-boo/hide-and-seek	111	36.4
5	Can't play pretend	202	66.2
6	Do not use your index finger to point or ask for objects.	188	61.6
7	Do not use your index finger to point at objects of interest.	213	69.8

Not playing properly with toys	173	56.7
9	Don't know how to show off things	203	66.6
10	Don't look into your eyes for more than 1 – 2 seconds	178	58.4
11	Overly sensitive to noise	95	31.1
12	Don't smile when you see relatives	62	20.3
13	Do not imitate facial expressions/actions	181	59.3
14	No response when called by name	218	71.5
15	Don't look at the object you are pointing at.	164	53.8
16	Not walking normally	64	21.0
17	Don't follow the object you are looking at.	121	39.7
18	Bring your hands close to your face and make strange movements.	67	22.0
19	Don't draw attention to your activities	132	43.3
20	Suspected deafness	34	11.1
21	Don't understand what people say	171	56.1
22	Staring blankly/walking absentmindedly	75	24.6
23	Don't look to gauge your reaction	127	41.6

Abnormal signs in children with ASD account for a high percentage of some signs such as Children not caring about other children (66.6%); Children not knowing how to pretend play (66.2%); Children not using their index finger to point at objects of interest (69.8%); Children not knowing how to show off objects (66.6%); Children not looking into the eyes of the person opposite for more than 1-2 seconds (children not making eye contact) (58.4%); Children not imitating your facial expressions/actions (59.3%); Children not responding when called by name (71.5%).

3.2.3. Evaluation of sensitivity and specificity of the M-CHAT checklist

Calculating sensitivity and specificity on only the number of M-CHAT negative and positive tests that tested for DSM-IV diagnosis

In total, we performed DSM-IV diagnostic examinations of 1282 children, of whom 495 were positive and 787 were negative for M-CHAT and completed the diagnostic examination.

Table 3.10. Evaluation of the validity of the M-CHAT Checklist for detecting RLTK

(based on DSM-IV diagnosed 1282 children only )

RLTK	No RLTK	Total
M-CHAT (+)	302	193	495
M-CHAT (-)	3	784	787
Total	305	977	1282

From the table above, we can calculate:

- Sensitivity (Sn): 302/305=99%

- Specificity (Sp): 784/977= 80.2%

- Positive predictive value (PPV): 302/495 = 61%

- Negative predictive value (NPV)= 784/787 =99.6%

Table 3.11. Comparison of screening and diagnosis results of RLTK

Diagnostic examination using DSM-IV

RLTK		No RLTK		Total number
n	%	n	%	Total number
Diagnostic group guess	M-CHAT23 (+) (n1)	302	61.00	193	39.00	495
Diagnostic group guess	M-CHAT23 (-) (n2)	3	0.38	784	99.62	787
Total number of children (n examined = 1282)		305		977		1282

True positive rate of M-CHAT Checklist with RLTK = 302/495=61% False negative rate of M-CHAT Checklist with RLTK = 3/787= 0.38%

Thus, we estimate the number of children with RLTK out of the total number of M-CHAT-negative cases who have not been diagnosed with DSM-IV is:

0.38% * (39729 -787) = 0.38%*38942= 148 children.

Thus, if we examine all the M-CHAT negative cases, we will have 148 more RLTK children. So the total estimated RLTK children in the entire M-CHAT negative sample is 148 +3 =151 children.

Sensitivity and specificity correction on the entire M-CHAT screened sample only Table 3. 12. Evaluation of the validity of the M-CHAT Checklist based on the estimated number

examined all 40,243 children

RLTK	No RLTK	Total
M-CHAT (+)	302	193	495
M-CHAT (-)	3+148= 151	39,697	39,748
Total	453	39,890	40,243

- Sensitivity (Sn): 302/453=67%

- Specificity (Sp): 39,697/39,890= 99.5%

- Positive predictive value (PPV): 302/495 = 61%

- Negative predictive value (NPV)= 39697/39748 =99.8%

3.3. Analysis of some related factors (individual, family, pre-, intra- and post-natal factors) with RLPTK in children 18-30 months old

In the analysis of some factors related to autism spectrum disorder in children, we analyzed the status of children diagnosed with autism spectrum disorder (305 children) and without autism spectrum disorder (39,938 children).

3.3.1. The relationship between some personal and family characteristics and autism spectrum disorder in children 18-30 months old

Table 3.13. Univariate regression analysis of the association between some personal factors and RLPTK in children

Element

RLPTK		OR	95% confidence interval
Quantity (n)	Rate (%)	OR	Bottom border	Upper bound
Province/city
Hanoi	46	0.84	1.18	0.77	1.79
Peace	41	0.70	0.98	0.64	1.51
Peace	43	0.73	1.03	0.67	1.57
Quang Nam	45	0.81	1.14	0.75	1.74
Dong Thap	38	0.68	0.95	0.61	1.48

Element

RLPTK		OR	95% confidence interval
Quantity (n)	Rate (%)	OR	Bottom border	Upper bound
Dong Nai	50	0.84	1.19	0.79	1.79
Dak Lak	42	0.71	1
Youth group
18-23 months	119	0.69	0.86	0.68	1.08
24-30 months	186	0.81	1
Young gender
Male	245	1.15	3.65 ***	2.75	4.84
Female	60	0.32	1
Living area
Urban	142	1.42	2.67 ***	2.13	3.34
Countryside	163	0.54	1
Child order
The first	140	0.82	1.20	0.84	1.71
Monday	126	0.72	1.06	0.74	1.52
Third and above	39	0.68	1

Note: (***) = p<0.001

The rate of RLPTK in children aged 18-30 months in 7 provinces/cities ranged from 0.68% to 0.84%. The highest rate of RLPTK in children was in Hanoi (0.84%) and Dong Nai (0.84%), the lowest was in Thai Binh (0.70%) and Dong Thap (0.68%). No statistically significant relationship was found between the risk of RLPTK in children by province/city, by age group of children and by child order.

Boys have a 3.65 times higher rate of ASD than girls (95% CI: 2.75 - 4.48); children living in urban areas have a 2.67 times higher risk of ASD than children living in rural areas (95% CI: 2.13 - 3.34).

Table 3.14. Univariate regression analysis of the association between some family factors and RLPTK in children

Element

RLPTK		OR	95% confidence interval
Quantity (n)	Rate (%)	OR	Bottom border	Upper bound
Mother's age at birth
Under 20 years old	17	0.63	0.90	0.54	1.48
20-29 years old	178	0.70	1
30-34 years old	60	0.72	1.02	0.76	1.37
35 years and older	50	1.36	1.94***	1.42	2.67
Father's age at birth
Under 20 years old	4	0.60	0.84	0.31	2.26
20-34 years old	222	0.72	1
35-45 years old	69	0.93	1.29	0.99	1.70
46 years and older	10	1.87	2.64 **	1.39	5.00
Mother's education
Primary/ Secondary	99	0.70	1
High School	103	0.73	1.05	0.79	1.38
Secondary/ College	58	0.90	1.30	0.94	1.80
Undergraduate/Graduate	44	0.81	1.17	0.82	1.67
Father's education
Primary/ Secondary	102	0.71	1
High School	111	0.77	1.09	0.83	1.42
Secondary/ College	52	0.97	1.37	0.98	1.91
Undergraduate/Graduate	35	0.65	0.92	0.63	1.35
Mother's occupation
Farming	64	0.74	1
State employee	36	0.68	0.91	0.60	1.37
Private employee	74	0.72	0.97	0.70	1.36
Free	84	0.74	1	0.72	1.39
Other	47	0.98	1.33	0.91	1.94
Father's occupation
Farming	72	0.77	1
State employee	25	0.52	0.68	0.43	1.07
Private employee	62	0.72	0.94	0.67	1.32
Free	142	0.88	1.15	0.87	1.53
Other	4	0.64	0.83	0.30	2.28
Family history of RLTK/RLTT/KTBS
Have	53	2.20	3.37 ***	2.50	4.50
Are not	252	0.70	1

Note: (**) = p<0.01; (***) = p<0.001

The rate of RLPTK in children is highest in the group of mothers who give birth at the age of 35 years or older or fathers who give birth at the age of 46 years or older and this difference is statistically significant. Children born to mothers aged 35 years or older have a 1.94 times higher risk of RLPTK than children born to mothers aged 20-29 years (95% CI: 1.42 - 2.67). Children have a 2.64 times higher risk of RLPTK when the age of the father is 46 years or older compared to the group of fathers aged 20-34 years (95% CI: 1.39 - 5.00).

There was no statistically significant relationship between RLPTK in children according to the educational level of the mother, father, and the occupation of the mother and father.

The rate of RLPTK in children with a family history of relatives (including paternal/maternal grandparents; parents, aunts, uncles, siblings) with neurological disorders or mental disorders or congenital disabilities is 3.4 times higher than in the group of children without relatives with the above disorders or disabilities (95% CI: 2.5 - 4.5).

3.3.2. The relationship between some prenatal factors and autism spectrum disorder in children 18-30 months old

Table 3.15. Univariate regression analysis of the association between some prenatal factors and children's RLPTK

Prenatal factors

RLPTK		OR	95% confidence interval
Quantity (n)	Proportion (%)	OR	Near below	Near above
Maternal history of miscarriage/stillbirth/abortion
Have	118	3.20	6.48 ***	5.13	8.18
Are not	187	0.50	1
Conception support
Reproductive support	12	5.77	8.28 ***	4.57	14.99
Natural Pregnancy	293	0.73	1
Flu or other viral infections during pregnancy
Have	45	2.50	3.68 ***	2.67	5.07
Are not	260	0.69	1
Frequent exposure to chemicals during pregnancy
Have	9	3.52	4.87 ***	2.48	9.56
Are not	296	0.74	1

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