Ch. 2: Who and How Many Stutter?

Question 1

Prevalence

Answer 1

• the number of all cases currently identified (even if they did not begin recently)
• Prevalence is usually lower than incidence

Question 2

Lifetime incidence

Answer 2

• the number of all cases ever exhibited of a disorder whether currently or in the past (even if they recovered).
• Incidence is flexible

Question 3

How many stutter?

Answer 3

• World Population Overall: 7,250,000,000
• World Stuttering Prevalence: 50,400,000 .7% ratio
• World Stuttering Incidence: 362,500,000 5.0% Ratio
• U.S. Population overall: 320,000,000
• U.S. Stuttering Prevalence: 2,240,000 .7% ratio
• U.S. Stuttering Incidence: 16,000,000 5.0% Ratio

Question 4

21st century prevalence studies

Answer 4

See powerpoint

Question 5

Recent Incidence Studies

Answer 5

See Powerpoint

Question 6

Familiality and Stuttering Incidence

Answer 6

• Majority of studies: 30-60% of PWS have familial stuttering
• Fewer than 10% of NFS have familial stuttering

Question 7

Who Stutter: The age Factor

Answer 7

Young children: 1.4% prevalence
Young Adults: .5% prevalence
Older adults: .3% prevalence

Question 8

Why does stuttering prevalence decline with age?

Answer 8

• Natural recovery includes more cases as age increases
• New stuttering onsets, however, are less frequent as age increases
• Usually occurs between 2-3yrs old

Question 9

Who Stutters: The gender factor

Answer 9

Childhood (near onset):
2.1 males to 1 female

Adulthood:
4 males to 1 female

Females are less likely to start stuttering, as well as more likely to recover from stuttering.

Question 10

Geographical & Cultural Factors

Answer 10

Stuttering has been documented in nearly all geographic areas of the world

Cross-culture stuttering findings are questionable due to methodological problems

Question 11

Race Factor

Answer 11

• A common belief: higher incidence of stuttering among African Americans
• Recent research of preschoolers: no significant difference between African Americans and European Americans

Question 12

Stuttering and Hearing Impairment

Answer 12

• Research: a low incidence (0.05 -0.12%) among the hearing impaired
• Informal reports: more manual disfluency than oral disfluency among the deaf

Question 13

Stuttering and Cognitive Impairment

Answer 13

• Past research: a high incidence of stuttering among those with cognitive impairments
• Children with Down syndrome have a higher disfluency level, but show low emotional reactivity to their stuttering