The association between obesity and screening mammography accuracy.
BACKGROUND
Obesity is increasing among American women, especially as they age. The influence of obesity on the accuracy of screening mammography has not been studied extensively.


METHODS
We analyzed 100 622 screening mammography examinations performed on members of a nonprofit health plan. The relationship between body mass index (weight in kilograms divided by the square of height in meters) and measures of screening accuracy was assessed. Body mass index was categorized as underweight or normal weight (<25), overweight (25-29), obesity class I (30-34), and obesity classes II to III (> or =35).


RESULTS
Compared with underweight or normal weight women, overweight and obese women were more likely to be recalled for additional tests after adjusting for important covariates, including age and breast density (overweight odds ratio [OR], 1.17; 95% confidence interval [CI], 1.11-1.23); obesity class I OR, 1.27; 95% CI, 1.19-1.35; obesity classes II-III OR, 1.31; 95% CI, 1.22-1.41). As body mass index increased, women were more likely to have lower specificity (overweight OR, 0.86; 95% CI, 0.81-0.90; obesity class I OR, 0.79; 95% CI, 0.74-0.84; and obesity classes II-III OR, 0.77; 95% CI, 0.71-0.82). No statistically significant differences were noted in sensitivity. Adjusted receiver operating characteristic analysis showed statistically significant improvement in the area under the curve (AUC) for underweight or normal weight women (AUC = 0.941) vs overweight women (AUC = 0.916, P =.02) and underweight or normal weight women vs obesity classes II and III women (AUC = 0.904, P =.02).


CONCLUSIONS
Obese women had more than a 20% increased risk of having false-positive mammography results compared with underweight and normal weight women, although sensitivity was unchanged. Achieving a normal weight may improve screening mammography performance.
Elmore
Joann G
JG
Division of General Internal Medicine, University of Washington School of Medicine, Harborview Medical Center, 325 Ninth Avenue, Box 359780, Seattle, WA 98104-2499, USA. jelmore@u.washington.edu
Carney
Patricia A
PA
Abraham
Linn A
LA
Barlow
William E
WE
Egger
Joseph R
JR
Fosse
Jessica S
JS
Cutter
Gary R
GR
Hendrick
R Edward
RE
D'Orsi
Carl J
CJ
Paliwal
Prashni
P
Taplin
Stephen H
SH
D000328:Adult; D000367:Age Factors; D000368:Aged; D015992:Body Mass Index; D001835:Body Weight; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D016022:Case-Control Studies; D015331:Cohort Studies; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods*; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis* / Q000453:epidemiology; D016017:Odds Ratio; D011336:Probability; D012016:Reference Values; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014481:United States / Q000453:epidemiology