National Health and Nutrition Examination Survey 1999-2000: effect of observer training and protocol standardization on reducing blood pressure measurement error.
OBJECTIVE
We describe the National Health and Nutrition Examination Survey (NHANES) blood pressure (BP) observer training and protocol standardization and evaluate the quality of BP measurement.


METHODS
The participants were persons aged 8 years and older who had their BP measured (n=7467) during NHANES 1999-2000. Cuff width/arm circumference ratio (CW/AC), end digit preference, and observer agreement were examined.


RESULTS
In stepwise principal components multiple regression analysis, CW/AC accounted for less than 2% of variability R(2) in all readings. The frequencies for all end digits were close to 20% ("0" end digit=21% systolic and 23% diastolic). No overall observer effect was present for mean systolic BP readings. A significant observer effect (P<.0001) was detected for mean diastolic BP readings of <90 mm Hg. For readings of > or =90 mm Hg, there was no significant observer effect (P=.157).


CONCLUSIONS
We conclude that NHANES BP measurements do not demonstrate the variability that is commonly caused by observer and technical error.
Ostchega
Yechiam
Y
Division of Health Examination Statistics, National Center for Health Statistics, NHANES Program, 3311 Toledo Road, Room 4319, Centers for Disease Control and Prevention, Hyattsville, MD 20782, USA. yxo1@cdc.gov
Prineas
Ronald J
RJ
Paulose-Ram
Ryne
R
Grim
Carlene M
CM
Willard
Grace
G
Collins
Doreen
D
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015982:Bias; D001795:Blood Pressure Determination / Q000295:instrumentation / Q000592:standards*; D002648:Child; D002985:Clinical Protocols; D003971:Diastole; D005260:Female; D006306:Health Surveys; D006801:Humans; D007326:Institutionalization; D008297:Male; D008875:Middle Aged; D011785:Quality Assurance, Health Care; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D013599:Systole