Abstract
Background
Autism Spectrum Disorder (ASD) is a neurodevelopmental condition in which early identification and intervention significantly improve developmental outcomes. The Modified Checklist for Autism in Toddlers, Revised with Follow-Up (M-CHAT-R/F), is commonly used in primary care settings for early screening; however, real-world data on its performance in Saudi primary care, particularly within military healthcare systems, remain limited. The purpose of this study is to evaluate the outcomes of ASD screening using M-CHAT-R/F among toddlers attending the Well-Baby Clinics (WBCs) at the Armed Forces Hospital in Dhahran, including the positive screening rate, reported ASD diagnoses, associated demographic factors, and monthly trends in screening yield.
Methods
A retrospective cross-sectional study was conducted at the Family Medicine Department WBCs of the Armed Forces Hospital in Dhahran. All toddlers aged 16–30 months who underwent ASD screening between January 2024 and July 2025 were included. Demographic data and M-CHAT-R/F results were extracted from electronic medical records. Screening followed the standardized two-stage M-CHAT-R/F protocol, including the structured Follow-Up Interview for medium-risk initial scores. Screen-positive children were referred to pediatric specialists, and ASD diagnosis status was determined based on medical record documentation or caregiver report. Data were analyzed using SPSS version 22.0. Chi-square and independent t-tests were used to assess associations, with significance set at p < 0.05.
Results
A total of 742 toddlers were screened (51.9% females, 48.1% males), with a mean age of 19.3 ± 2.2 months. Forty-nine children screened positive on M-CHAT-R/F, yielding a screen-positive rate of 6.6%. Of these, 12 were identified as having received an ASD diagnosis following specialist evaluation, resulting in an ASD diagnosis rate of 1.6% and a positive predictive value (PPV) of 24.5%. No significant associations were found between screening outcomes and sex (p = 0.145), age group (p = 0.551), or parental age (p > 0.05). Monthly screening positivity ranged from 0% to 14.6%, while ASD diagnosis rates following specialist evaluation ranged from 0% to 3.4%, with no consistent temporal trend.
Conclusions
ASD screening using M-CHAT-R/F in primary care WBCs demonstrated a low rate of ASD diagnosis following specialist evaluation with low-to-moderate PPV. Screening outcomes showed variability over time and were not significantly influenced by demographic factors. These findings highlight the importance of continued evaluation of referral pathways and follow-up processes to support early ASD detection in primary care settings.
Keywords: Autism spectrum disorder, M-CHAT-R/F, Developmental screening, Toddlers, Primary health care, Well-Baby Clinics
Background
Autism Spectrum Disorder (ASD) is a neurodevelopmental condition characterized by persistent deficits in social communication and interaction, alongside restricted or repetitive patterns of behavior or interests. Early diagnosis and intervention have been shown to substantially improve outcomes in affected children, including language acquisition, adaptive functioning, and long-term quality of life [1].
The Modified Checklist for Autism in Toddlers, Revised with Follow-Up (M-CHAT-R/F) is a widely used parent-completed screening instrument designed for toddlers aged approximately 16–30 months [2]. As part of routine well-child care, it aims to identify children at risk for ASD who should be referred for specialist diagnostic assessment.
While M-CHAT has demonstrated good sensitivity in multiple settings, its specificity and positive predictive value (PPV) may vary according to population characteristics, cultural context, and follow-up procedures [2, 3].
In Saudi Arabia and other Arab-speaking countries, data on ASD screening in primary care remain limited. A study from a Saudi primary care setting demonstrated that although the Arabic version of M-CHAT was feasible and acceptable, only a small proportion of toddlers who screened positive were ultimately confirmed to have ASD [4]. Furthermore, expert consensus guidelines for ASD assessment and management in Saudi Arabia emphasize the need for locally generated evidence regarding screening yield, referral pathways, and diagnostic outcomes [5].
The Armed Forces Hospital in Dhahran (AFHD), Saudi Arabia, under the Family Medicine Department, provides well-baby clinic (WBC) services that include routine developmental screening for eligible beneficiaries. Although M-CHAT-R/F screening has been incorporated into standard well-child visits in this setting, a formal evaluation of screening outcomes, ASD diagnosis status following specialist evaluation, and temporal trends has not previously been conducted. Understanding the prevalence of positive screening results, reported ASD diagnoses, and their associations with demographic factors is essential for quality improvement, resource allocation, and early childhood service planning.
Methods
This study employed a retrospective cross-sectional design to assess the outcomes of ASD screening among toddlers attending the WBCs at the AFHD, Saudi Arabia, under the Family Medicine Department. The hospital is a military facility providing comprehensive preventive and developmental services for eligible beneficiaries in the Eastern Region.
The study population included all male and female toddlers aged 16–30 months who attended the WBCs and underwent ASD screening during the study period. Sample size was calculated using EpiInfo™ version 7.0, yielding a minimum required sample of 480 toddlers at a 95% confidence level and a 5% margin of error. All eligible children within the study timeframe were included, resulting in a final sample of 742 toddlers, which exceeded the calculated requirement.
A retrospective review of electronic medical records was undertaken for toddlers who visited the WBCs between January 2024 and July 2025. Data extraction was performed after completion of the study period, and only finalized records within this timeframe were included in the analysis. Data were extracted using a standardized data collection sheet and included demographic characteristics (age, sex, parental age), date of screening, and results of the M-CHAT-R/F.
Screening was conducted using the standardized two-stage M-CHAT-R/F protocol. All toddlers completed the 20-item M-CHAT-R questionnaire during their well-baby visit. Initial scores were categorized as low risk (0–2), medium risk (3–7), or high risk (8–20). Toddlers in the medium-risk category underwent the structured Follow-Up Interview (F) in accordance with the recommended protocol. Children were classified as screen-positive if they had a high-risk initial score (8–20) or remained positive after the Follow-Up Interview (score ≥ 2). Those with low-risk scores or negative follow-up results were classified as screen-negative.
Screening results recorded in the system were categorized as screen-negative or screen-positive. Toddlers who screened positive were referred to pediatric specialists for further evaluation. ASD diagnosis status following specialist referral was determined based on documentation within the hospital electronic medical record when available and, when documentation was incomplete, through follow-up contact with caregivers to ascertain whether an ASD diagnosis had been made and whether intervention services such as behavioral therapy had been initiated.
The dependent variables were M-CHAT-R/F screening outcome and reported ASD diagnosis following specialist evaluation. Independent variables included toddler age, sex, and parental age. Age at screening was calculated in months and further categorized into approximately 18-month (< 21 months) and 24-month (≥ 21 months) groups for comparative analysis. Data were coded, organized, and entered into a secure database for processing.
Statistical analysis was conducted using IBM Statistical Package for the Social Sciences (SPSS) Statistics for Windows, version 22.0. Continuous variables were summarized as means and standard deviations, while categorical variables were presented as frequencies and percentages. Associations between categorical variables were assessed using the chi-square test, and differences in mean parental age between screen-positive and screen-negative groups were evaluated using independent samples t-tests. Screening performance indicators were calculated, including screen-positive rate, reported ASD diagnosis rate, PPV, and false positive rate. A p-value of < 0.05 was considered statistically significant.
Ethical approval was obtained from the Institutional Review Board (IRB) of the Armed Forces Hospitals in the Eastern Region, Saudi Arabia. Given the retrospective design and use of existing medical records, informed consent was waived by the IRB. All extracted data were de-identified prior to analysis and assigned unique study codes to ensure participant anonymity. Data were stored in a password-protected electronic database accessible only to the research team and handled in accordance with institutional data governance and confidentiality policies. No identifiable patient information was included in the analysis or reporting of results.
Results
A total of 742 toddlers attended the WBC and were screened for ASD using M-CHAT-R/F. The mean age at screening was 19.3 ± 2.2 months (range 16.4–24.6), and 385 (51.9%) were girls while 357 (48.1%) were boys. Mean paternal age at the child’s birth was 40.5 ± 7.4 years and mean maternal age was 35.0 ± 4.6 years (Table 1).
Table 1.
Baseline characteristics of the study population by screening outcome
| Variable | Total (n = 742) | Screen-positive (n = 49) | Screen-negative (n = 693) | p-value |
|---|---|---|---|---|
| Male, n (%) | 357 (48.1%) | 29 (59.2%) | 328 (47.3%) | 0.145 |
| Female, n (%) | 385 (51.9%) | 20 (40.8%) | 365 (52.7%) | |
| Toddler age (months), mean ± SD | 19.3 ± 2.2 | 19.0 ± 1.9 | 19.3 ± 2.2 | 0.353 |
| Maternal age (years), mean ± SD | 35.0 ± 4.6 | 35.5 ± 4.7 | 35.0 ± 4.6 | 0.422 |
| Paternal age (years), mean ± SD | 40.5 ± 7.4 | 41.1 ± 7.4 | 40.4 ± 7.4 | 0.559 |
Overall, 49 children screened positive on M-CHAT-R/F, giving a screen-positive rate of 6.6% (49/742). Among the 49 screen-positive children, 12 were identified as having a reported ASD diagnosis following specialist evaluation, corresponding to a reported ASD diagnosis rate of 1.6% among all screened toddlers. The PPV of a positive M-CHAT-R/F result was 24.5% (12/49), and the false positive rate was 75.5% (37/49) (Table 2).
Table 2.
Screen-positive rate based on M-CHAT-R/F and reported ASD diagnosis following specialist evaluation
| Category | Screen-positive n (%) | Reported ASD diagnosis n (%) |
|---|---|---|
| Overall | 49 (6.6%) | 12 (1.6%) |
| Male | 29 (8.1%) | 10 (2.8%) |
| Female | 20 (5.2%) | 2 (0.5%) |
| 18 months group (< 21 months) | 43 (6.9%) | 11 (1.8%) |
| 24 months group (≥ 21 months) | 6 (5.0%) | 1 (0.8%) |
Male toddlers had a higher proportion of positive M-CHAT-R/F results than females (8.1% vs. 5.2%), but this difference was not statistically significant (χ² = 2.12, p = 0.145). Among screen-positive children, reported ASD diagnosis following specialist evaluation was more frequent in boys than in girls (10/29 [34.5%] vs. 2/20 [10.0%]), although this association also did not reach statistical significance (χ² = 2.63, p = 0.105). When age at screening was grouped as approximately 18 months (< 21 months) versus approximately 24 months (≥ 21 months), the proportion of positive screens was 6.9% (43/621) and 5.0% (6/121), respectively, with no significant difference between age groups (χ² = 0.36, p = 0.551) (Table 2).
Parental age was not significantly associated with screening outcome. Fathers of screen-positive children had a mean age of 41.1 ± 7.4 years compared with 40.4 ± 7.4 years in the screen-negative group (t = 0.59, p = 0.559), while mothers’ ages were 35.5 ± 4.7 and 35.0 ± 4.6 years, respectively (t = 0.81, p = 0.422) (Table 1).
Monthly variation in screening outcomes was observed across the study period (January 2024–July 2025). The proportion of toddlers screening positive on M-CHAT-R/F ranged from 0% to 14.6%, with the highest rate recorded in June 2024 (14.6%), while reported ASD diagnosis rates following specialist evaluation remained consistently low, varying between 0% and 3.4% per month. Several months in 2025 showed no positive or reported ASD diagnoses despite ongoing screening activity. Overall, rates fluctuated over time without a consistent increasing or decreasing pattern (Fig. 1).
Fig. 1.
Monthly trend of screen-positive M-CHAT-R/F results and reported ASD diagnosis rate among toddlers attending the WBC from January 2024 to July 2025
Discussion
This study provides real-world evidence on the performance of the M-CHAT-R/F when implemented as part of routine developmental surveillance in WBCs within a Saudi Arabian military primary health care setting. Among 742 screened toddlers, 6.6% screened positive, while 1.6% were ultimately identified as having a reported ASD diagnosis following specialist evaluation. These findings provide important insight into the yield, predictive value, and operational implications of ASD screening in primary care.
The reported ASD diagnosis rate of 1.6% observed in this cohort is consistent with international estimates, which generally range between 1% and 2% in many populations worldwide [6–8]. Although national epidemiological data on ASD in Saudi Arabia remain limited, available regional studies suggest comparable prevalence rates, with underdiagnosis likely contributing to observed variability across settings [9]. The alignment of the reported ASD diagnosis rate in this study with global figures supports the external validity of the screening outcomes.
The positive screening rate of 6.6% is consistent with reports from other primary care and community-based studies using M-CHAT, where positivity rates typically range from 5% to 10% [3, 10]. This finding supports the feasibility of incorporating ASD screening into routine WBC services without generating an excessive referral burden.
The PPV of M-CHAT-R/F in the present study was 24.5%, indicating that approximately one in four toddlers who screened positive were identified as having a reported ASD diagnosis following specialist evaluation. This represents a low-to-moderate PPV, which is comparable to previous real-world studies reporting PPV between 20% and 40% when M-CHAT is used as a first-stage screening tool in unselected populations [11, 12]. In population-based developmental screening, lower PPV is often expected due to the “screening paradox,” whereby high sensitivity is prioritized over specificity to avoid missing true cases during critical early developmental periods. As a result, higher false-positive rates may occur, reflecting the intended design of early screening programs rather than poor test performance.
False-positive screening results may be influenced by parental interpretation of questionnaire items, cultural perceptions of child behavior, and variability in diagnostic follow-up processes [13]. In Middle Eastern and Arab contexts, cultural norms related to social interaction and communication may further influence parental responses, potentially increasing false-positive rates [9, 14]. These findings highlight the importance of structured follow-up procedures and clear referral pathways to optimize screening efficiency and reduce unnecessary parental anxiety.
No significant associations were observed between M-CHAT-R/F outcomes or reported ASD diagnosis following specialist evaluation and child sex, age at screening, or parental age. Although male toddlers demonstrated higher proportions of both positive screening results and reported ASD diagnoses, these differences did not reach statistical significance. This contrasts with established epidemiological data reporting a male predominance in ASD, with male-to-female ratios of approximately 3–4:1 [6, 7], and is likely attributable to the relatively small number of cases in this cohort.
Similarly, parental age was not significantly associated with screening outcomes, despite evidence from larger population-based studies suggesting associations between advanced maternal or paternal age and ASD risk [15, 16]. These findings suggest that demographic characteristics alone are insufficient predictors of screening outcomes in primary care and support the use of universal rather than risk-based developmental screening approaches.
Monthly analysis revealed variability in M-CHAT-R/F screen-positive rates and reported ASD diagnosis rates following specialist evaluation without a consistent temporal trend. Such fluctuations are commonly reported in screening programs and may reflect changes in clinic attendance, staff experience, parental awareness, or documentation practices over time [17]. This underscores the importance of sustained screening efforts and ongoing program evaluation.
The findings of this study support the integration of ASD screening into routine WBC services within Saudi primary care. While M-CHAT-R/F effectively identifies children at increased risk, its low-moderate PPV highlights the necessity of robust referral systems, timely specialist access, and clear communication with families. Family physicians play a pivotal role in interpreting screening results, counseling caregivers, and coordinating follow-up care.
At a system level, these results underscore the need for ongoing evaluation of screening pathways and strengthening collaboration between primary care and developmental services. Locally generated evidence such as this study may contribute to service evaluation and quality improvement efforts within similar primary care settings.
This study benefits from a large sample size, inclusion of all eligible toddlers over an extended period, and the use of real-world electronic medical record data from routine primary care practice. However, several limitations should be acknowledged. The retrospective design limited control over follow-up standardization, and not all screen-positive children may have undergone uniform diagnostic assessment. In addition, detailed information regarding the specific diagnostic criteria (e.g., DSM-5 or ICD-10) or standardized assessment tools used by specialists was not consistently available in the medical records. ASD diagnosis status was determined based on documentation within the hospital system or caregiver report, and we were therefore unable to independently verify the use of standardized diagnostic instruments. Furthermore, ASD diagnoses made outside the hospital system may not have been captured. Despite these limitations, the study provides valuable insight into ASD screening performance in Saudi primary care and addresses a notable gap in the local literature.
Conclusion
Routine ASD screening using M-CHAT-R/F in WBCs within a PHC setting demonstrated a low rate of reported ASD diagnosis following specialist evaluation and a low-moderate PPV. Screening outcomes were not significantly associated with child sex, age at screening, or parental age, and monthly screening positivity varied over time without a consistent trend. These findings provide real-world data on M-CHAT-R/F screening performance within this primary care setting and suggest the value of ongoing evaluation of referral pathways and follow-up processes related to early ASD detection.
Acknowledgements
The authors sincerely thank Dr. Sana A. Alharbi, Family Medicine Consultant, for her kind cooperation during the conduct of this research. We also thank the Family Medicine Department and the Well-Baby Clinic staff at the Armed Forces Hospital in Dhahran for their support and assistance in facilitating data access.
Abbreviations
- ASD
Autism Spectrum Disorder
- (M-CHAT-R/F)
Modified Checklist for Autism in Toddlers, Revised with Follow-Up
- WBC
Well-Baby Clinic
- PHC
Primary Health Care
- AFHD
Armed Forces Hospital, Dhahran
- SPSS
Statistical Package for the Social Sciences
- PPV
Positive Predictive Value
- QI
Quality Improvement
- IRB
Institutional Review Board
Authors’ contributions
RZS contributed to study conception and design, data analysis, manuscript drafting, and revision of the final version. MAM served as the principal investigator, supervised data collection and project implementation, and critically reviewed and approved the manuscript. Both authors approved the final manuscript.
Funding
This study was not supported by any sponsor or funder.
Data availability
the data supporting the findings of this study are not publicly available, as they contain information that could compromise the privacy of research participants. However, they are available from the corresponding author, RZS, upon reasonable request.
Declarations
Ethics approval and consent to participate
The study was held in accordance with the World Medical Association Declaration of Helsinki 1975 (revised in 2000). Ethical approval for this study was obtained from the Armed Forces Hospitals Eastern Province Institutional Review Board (IRB), vide letter No. AFHER-IRB-2024-042.
Consent for publication
not applicable.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
the data supporting the findings of this study are not publicly available, as they contain information that could compromise the privacy of research participants. However, they are available from the corresponding author, RZS, upon reasonable request.