Allison Derrick

Masters of Public Health Candidate

UW School of Medicine and Public Health

Regional Distribution of Orofacial Cleft Defects

in Wisconsin

Acknowledgements

• Delora Mount, MD; UW Plastic and Reconstructive Surgery

• Glen Leverson, PhD; Biostatistics

• Henry Anderson, MD, MPH; DHFS

• Kristen Malecki, PhD; DHFS

• Liz Oftedahl, MPH; DHFS

• Laura Ninneman, DHFS

Outline

• Background

• Objectives

• Methods

• Results

• Discussion

• Conclusion

Background

Background• Orofacial clefts are the most common craniofacial

birth defects• Incidence ranging from approximately 0.5 to 2 per

1,000 births*• Multifactorial etiology

– Both genetic and environmental factors implicated

• Public health Problem– significant lifelong morbidity– complex etiology– requires extensive treatment

• surgical, psychological, speech and dental interventions• Lifetime cost of >$101,000

Marazita, M. L. and M. P. Mooney. Clin Plast Surg 2004; 31(2): 125-40Waitzman NJ, Romano PS, Scheffler RM. Inquiry 1994;31:188-205.

Objectives• Perform the first analysis of the distribution of

orofacial cleft births in Wisconsin• Evaluate the incidence of orofacial cleft births in

the Fox River Valley with respect to the rest of Wisconsin

• Examine the geographical distribution for potential associations between environmental factors and orofacial cleft defects

Methods• Performed a comprehensive literature review on the

etiology and CL/P, environmental risk factors, research methodology

• IRB approval• Data Collection:

– Vital Records: 1997-2006*– WBDR: 2005-2006– WISH database: 1997-2006

• Calculated incidences by county*• Logistical regression to adjust for confounders*• Determined OR for OFCs w/in FRV vs. WI-FRV*

Results

Results

Incidence Rates

WI…………..1.046/1,000

FRV………..…1.463/1,000

WI - FRV……..0.997/1,000

Adjusted OR …1.52

(95% CI 1.23, 1.89; p=0.0001)

Results

Demographic Trends• Maternal age - NS• Maternal race - NS• Maternal educational achievement - NS• Maternal smoking status

OR 1.032 (95% CI 1.017,1.048)P-value = 0.0009

Results

• Interpretation of results– Incidence of 1.46/1,000

births in FRV is significantly higher than the rest of WI, but still WNL

•Cluster by chance?•Potential Environmental associations

– PCBs?– TTHMs?– Pesticides?

Discussion

US EPA: www.epa.gov/region5/foxriver/lower_fox_river_map WI DNR: http://www.dnr.state.wi.us/org/gmu

PCBs

Results*

*Texas Sharpshooter

WI DNR: http://dnr.wi.gov/org/water/dwg/swap/delineation.htmBove et al. Am J Epidemiol. 1995; 141 (9): 850-62.

Distribution of Drinking Water from Surface Water SourcesTTHMs*

*Texas Sharpshooter

U.S. Geological Survey Fact Sheet: Pesticides in ground water in the Western Lake Michigan Drainages. 1996

*Texas Sharpshooter

Pesticides in Groundwater*

DiscussionLimitations of study

– Sensitivity of Birth Certificate Data – Differences in reporting among counties– Maternal migration during pregnancy

• Misclassification bias

– No differentiation between CL/P and CP alone, or those cases associated with syndromes

– Potential Confounders• prenatal care/nutritional status• alcohol intake during pregnancy

– Descriptive geographic study • Cannot define causality

Watkins ML et al. Am J Public Health 1996;86:731-4.

Conclusions• Established a geographic distribution of OFC

births in WI• Found a statistically significant elevated risk of

OFCs in the FRV• Useful for formulating hypotheses for future

testing, but no causal relationship can be established

• Need to encourage reliable birth defect reporting and regular environmental exposure measurements– WI EPHT system Sept 2008…