Assessment & Research

Gender and geographic differences in the prevalence of intellectual disability in children: analysis of data from the national disability registry of Taiwan.

Lai et al. (2012) · Research in developmental disabilities 2012
★ The Verdict

Taiwan’s kids show a slow but steady rise in ID prevalence that keeps favoring boys and rural areas—use these 1.3–1.4 multipliers when you size services.

✓ Read this if BCBAs who write grants, design regional programs, or place early-intervention teams in Taiwan or similar East-Asian areas.
✗ Skip if Clinicians looking for single-case intervention tactics; this paper is pure epidemiology.

01Research in Context

01

What this study did

The team pulled every child with intellectual disability from Taiwan’s national registry.

They counted cases yearly from 2004 to 2010.

Then they split the counts by boys versus girls and by rural versus city areas.

02

What they found

Prevalence crept up from 4.40 to 5.79 kids per 1,000.

Boys stayed 1.3–1.4 times higher than girls.

Rural kids also stayed 1.3–1.4 times higher than city kids.

03

How this fits with other research

Lin (2009) saw the same male and rural gaps in the same registry during 2000-2007, so the new paper is an update, not a surprise.

Tseng et al. (2015) used the exact same method and years but looked at speech-language disability instead of ID; they found the same boy and rural excess, hinting the gap is not diagnosis-specific.

Kapoor et al. (2024) found an even larger male gap in India, showing the boy excess extends beyond Taiwan.

Freeman et al. (2015) flipped the age lens to Swedish adults 55+, yet men and northern counties still had higher ID counts, echoing the male and rural pattern.

04

Why it matters

When you budget for classrooms, clinics, or early-intervention slots, plan for about 1.3 boys for every girl and expect more referrals from rural towns.

Use these concrete ratios in grant proposals and staffing plans instead of generic “high-risk” language.

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Open your caseload map and check if rural schools have 30% more slots than city ones—if not, rebalance referral routes now.

02At a glance

Intervention
not applicable
Design
other
Population
intellectual disability
Finding
not reported

03Original abstract

Intellectual disability (ID) is not uncommon in children, but data at the national level are limited, especially those on geographic differences. On the basis of the Disabled Welfare Law, Taiwan began to certify disabled residents and provide various services in 1980. All the cases are registered, and the registry provides a rare opportunity for studying ID at the national level. Using the data from 2004 to 2010, we calculated the prevalence of ID in children by age, gender, and geographic area and assessed the changes over time. We limited analyses to children at least 3 years of age, because certification before 3 years old is discouraged by the government. We found that from 2004 to 2010, the registered cases between 3 and 17 years old ranged from 20,531 to 23,547, and the prevalence of ID increased constantly from 4.40/1000 to 5.79/1000 (p<0.01), which generally increased every year in all age groups (p<0.01). In each year there were more boy cases than girl cases, and the boy-to-girl ratio generally decreased with age (p<0.01 for chi-square test for trend in all years). The prevalence rate ratio ranged from 1.33 to 1.37 (p<0.01 in all years), and the changes in the rate ratio were small over the years. We observed a higher prevalence in the rural areas over the years, and the prevalence rate ratio ranged from 1.34 to 1.43 (p<0.01 in all years), with an increasing trend over time (p<0.01).

Research in developmental disabilities, 2012 · doi:10.1016/j.ridd.2012.07.001