Racial and Ethnic Disparities in the Knowledge of Shaken Baby Syndrome

among Recent Mothers

Findings from the 2004-2008 Rhode Island PRAMS

Hanna Kim, Samara Viner-Brown, Rachel Cain

Center for Health Data and Analysis

Rhode Island Department of Health

Background

• Shaken Baby Syndrome (SBS) is a form of child abuse that can result in permanent brain damage or death.

• SBS usually occurs when a parent or caregiver violently shakes a baby or toddler due to frustration or anger.

• If a baby is forcefully shaken, his or her fragile brain moves back and forth inside the skull, which causes bruising, swelling and bleeding.

Background

• Serious injuries associated with SBS may include blindness or eye injuries, brain damage, damage to the spinal cord, and delay in normal development.

• In 2001, 903,000 children suffered from SBS in the U.S. and an additional 1,300 died from it.

• About 20% of cases are fatal in the first few days after injury, and the majority of the survivors are left with disabilities.

Source: Healthline website:http://www.healthline.com/galecontent/shaken-baby-syndrome-2

Shaken Baby Syndrome

Shaken Baby Syndrome

Source: The National Center on SBS website

Study Questions

• What is the prevalence of Lack of Knowledge of Shaken Baby Syndrome (LKSBS) among Rhode Island recent mothers?

• Are there any Racial and Ethnic Disparities in the LKSBS?

• How does the Immigrant Status interact across race/ethnicity in the LKSBS?

Methods

• Data Source: 2004-2008 RI Pregnancy Risk Assessment Monitoring System (PRAMS)– Total Respondents for 5 years: 6,959– Weighted Response Rate (5-year average): 73.2%– Average PRAMS population per year: 11,816

Year PRAMS Pop. Respondents Weighted R.R.

2004 12,064 1,506 75.5

2005 12,013 1,424 75.1

2006 11,732 1,360 72.5

2007 11802 1,372 72.1

2008 11,467 1,297 70.4

What is the PRAMS? (Pregnancy Risk Assessment Monitoring System)

• A surveillance project of the CDC and state Health Departments to monitor the health of mothers and infants.

• Collects state-specific, population-based data on maternal behaviors and experiences before, during, and after pregnancy.

• A sample survey of recent mothers and administered 2-5 months after baby’s delivery by mail or telephone.

• The PRAMS sample is chosen from all women who had a live birth recently.

Variables Used

Outcome Variable: • Lack of Knowledge of SBS (LKSBS): “No” to the question

“Have you ever heard or read about what can happen if a baby is shaken?”

Exposure Variables: • Race/Ethnicity: NH-White

NH-Black NH-Asian/PI

Hispanic• Immigrant Status: Non-Immigrant (US-born)

Immigrant (Foreign-born)

Confounders: Maternal Age, Education, Income, Marital Status, and Parity

Statistical Analysis

• Chi-square tests for bivariate relationships between socio-demographic factors and LKSBS.

• Multivariable logistic regression analyses to determine independent and joint effects of race/ethnicity and immigrant status on LKSBS.

• SUDAAN (Survey Data Analysis) v10 software was used for statistical analyses to account for complex sample design of the survey.

Results

• Race/Ethnicity

– NH-White: 66%– NH-Black : 9%– NH-Asian/PI : 4%– Hispanic: 20%– NH- Others, including AI: 1% (excluded)

• Immigrant Status

– Immigrant: 25%– Non-Immigrant: 75%

Rhode Island PRAMS Population Distribution (2004-2008)

Proportion of Immigrant by Race/Ethnicity

– NH-White: 5%

– NH-Black : 48%

– NH-Asian/PI : 69%

– Hispanic: 72%

Rhode Island PRAMS Population Distribution (2004-2008)

Minority groups have higher proportion of immigrant

• Year (2004-2008)• Race/Ethnicity• Immigrant Status• Maternal Age• Education• Household Income• Marital Status• Parity

Prevalence of LKSBS: Bivariate Analysis

Exposure Vars.

Confounding Vars.

6.3 5.9 5.36.5 7.0 6.2

0

5

10

15

20

2004 2005 2006 2007 2008 5-YearAverage

Per

cent

Prevalence of LKSBS by Year, RI 2004-08

P = .6197

2.2

15.8 16.7

13.6

0

5

10

15

20

Non-HispanicWhite

Non-HispanicBlack

Non-HispanicAsian/PI

Hispanic

Per

cen

tPrevalence of LKSBS

by Race/Ethnicity

P < .0001

2.7

17.1

0

5

10

15

20

Non-Immigrant Mother Immigrant Mother

Per

cen

tPrevalence of LKSBS

by Immigrant Status

P < .0001

10.5

7.2

4.93.4

0

5

10

15

20

<20 yrs 20-29 yrs 30-34 yrs >= 35 yrs

Per

cen

tPrevalence of LKSBS

by Maternal Age

P < .0001

11.2

7.1

3.7

0

5

10

15

20

< High School High School > High School

Per

cen

t

P < .0001

Prevalence of LKSBS

by Maternal Education

9.8

4.9

2.3

16.6

0

5

10

15

20

< $20,000 $20,000-$49,999 >= $50,000 Unknown

Per

cen

t

P < .0001

Prevalence of LKSBS

by Household Income

4.5

8.8

0

5

10

15

20

Married Unmarried

Per

cen

t

P < .0001

Prevalence of LKSBS

by Marital Status

7.2

5.2

0

5

10

15

20

1st Birth 2nd or Later

Per

cen

t

P = 0.0040

Prevalence of LKSBS

by Parity

• The prevalence of LKSBS was significantly higher among NH-Blacks (15.8%), NH- Asians (16.7%), Hispanics (13.6%), Immigrants (17.1%), Teens (10.5%), mothers with < High School Education (11.2%), Incomes < $20,000 (9.8%), Unmarried (8.8%), First Time (7.2%) mothers.

Prevalence of LKSBS: Bivariate Analysis

Multivariable Logistic Regression

• To determine the independent effects of race/ethnicity and immigrant status on LKSBS, while controlling for confounding factors (maternal age, education, income, marital status and parity).

• To determine the joint effects of race/ethnicity and immigrant status on LKSBS, while controlling for confounding factors.

Outcome Variable: • Lack of Knowledge of SBS (LKSBS): Yes/No

Exposure Variables: • Race/Ethnicity

- NH-White: Referent Group - NH-Black

- NH-Asian/PI - Hispanic

• Immigrant Status - Non-Immigrant: Referent Group

- Immigrant

Confounders: Maternal Age, Education, Income, Marital Status, and Parity

Assessing Independent Effects of Race/Ethnicity and Immigrant Status

Effects of Race/Ethnicity and Immigrant Status on LKSBS

* AORs and 95% CIs were calculated after controlling for maternal age, education, household income, marital status, and parity.

Adjusted Odds Ratios (AORs) and 95% Confidence Intervals (CIs)*

AOR 95% CINH-White

NH-Black

NH-Asian/PI

Hispanic

Ref

3.1

3.4

1.8

Ref

2.0-4.8

2.0-5.8

1.1-2.8

Non-Immigrant

Immigrant

Ref

3.9

Ref

2.7-5.6

Effects of Race/Ethnicity on LKSBS: Stratified by Immigrant Status

* AORs and 95% CIs were calculated after controlling for maternal age, education, household income, marital status, and parity.

Adjusted Odds Ratios (AORs) and 95% Confidence Intervals (CIs)*

Non-Immigrants (n=5,046)

AOR (95% CI)

Immigrants (n=1,898)

AOR (95% CI)

NH-White

NH-Black

NH-Asian/PI

Hispanic

Ref

2.6 (1.3-5.2)

2.4 (0.7-7.6)

3.1 (1.7-5.6)

Ref

2.5 (1.3-4.9)

2.9 (1.4-5.9)

1.2 (0.6-2.1)

Outcome Variable: • Lack of Knowledge of SBS (LKSBS): Yes/No

Exposure Variables:

• Race/Ethnicity and Immigrant Status

- Non-Immigrant, NH-White: Referent Group - Non-Immigrant, NH-Black - Non-Immigrant, NH-Asian/PI - Non-Immigrant, Hispanic - Immigrant, NH-White - Immigrant, NH-Black

- Immigrant, NH-Asian/PI - Immigrant, Hispanic

Confounders: Maternal Age, Education, Income, Marital Status, and Parity

Assessing Joint Effects of Race/Ethnicity and Immigrant Status

Joint Effects of Race/Ethnicity and Immigrant Status on LKSBS

* AORs and 95% CIs were calculated after controlling for maternal age, education, household income, marital status, and parity.

Adjusted Odds Ratios (AORs) and 95% Confidence Intervals (CIs)*

AOR 95% CINon-Immigrant, NH-White

Non-Immigrant, HN-Black

Non-Immigrant, NH-Asian/PI

Non-Immigrant, Hispanic

Immigrant, NH-White

Immigrant, HN-Black

Immigrant, NH-Asian/PI

Immigrant, Hispanic

Ref

2.5

2.3

3.0

5.0

13.6

14.7

6.5

Ref

1.3-4.9

0.7-7.4

1.7-5.3

2.8-9.1

8.5-21.7

8.5-25.5

4.4-9.6

Indep. Effects: Either Minority OR Immigrant

Joint Effects: Both MinorityAND Immigrant

• Joint Effects of NH-Back & Immigrant: – Expected Odds Ratio = 2.5+5.0-1.0 = 6.5– Observed Odds Ratio = 13.6

• Joint Effects of NH-Asian/PI & Immigrant:– Expected Odds Ratio = 2.3+5.0-1.0 = 6.3– Observed Odds Ratio = 14.7

• Joint Effects of Hispanic & Immigrant:– Expected Odds Ratio = 3.0+5.0 1.0 = 7.0– Observed Odds Ratio = 6.5

Assessing Interaction: Additive Scale

Positive Additive Interaction

Positive Additive Interaction

No Additive Interaction

• Joint Effects of NH-Back & Immigrant: – Expected Odds Ratio = 2.5*5.0 = 12.5– Observed Odds Ratio = 13.6

• Joint Effects of NH-Asian/PI & Immigrant:– Expected Odds Ratio = 2.3*5.0 = 11.5– Observed Odds Ratio = 14.7

• Joint Effects of Hispanic & Immigrant:– Expected Odds Ratio = 3.0*5.0 = 15.0– Observed Odds Ratio = 6.5

Assessing Interaction: Multiplicative Scale

No Multiplicative Interaction

Negative Multiplicative Interaction

Positive Multiplicative Interaction ???

Conclusions

• Overall, 6.2% of RI recent mothers lacked a Knowledge of SBS, and the rate did not change during 2004-2008.

• There were significant Racial and Ethnic Disparities in the LKSBS; the odds of LKSBS were significantly higher among NH-Black, NH-Asian/PI, and Hispanic mothers (vs. NH-White).

Conclusions

• There was an interaction between race/ethnicity and immigrant status in the LKSBS; being an Immigrant & Black, or being an Immigrant & Asian/PI had the strong positive (synergistic) additive joint effects.

• A logistic regression model with joint effects fitted the data better than a model with independent effects only.

Limitations

• Measurement Issue: – Knowledge SBS: level of knowledge– Length of Immigration

• Sample Size Issue:– Small sample size for some race/ethnicity

categories, e.g. non-immigrant Asian/PI mothers (n<100)

Public Health Implications

• Substantial proportions of RI minority women who recently gave birth are also immigrants. These women are at highest risk for LKSBS.

• Public health efforts should target minority and immigrant mothers to educate them about the dangers of shaking a baby.

THANK YOU!

Contact Information:

Hanna Kim, PhD: Hanna.Kim@health.ri.gov