Computerized planimetry versus clinical assessment for the measurement of cervical ectopia

OBJECTIVE: As part of a study to assess the role of cervical ectopia in the acquisition of cervical infections, we determined the reliability of cervi cal ectopia measurements made by computer planimetry and by clinical (visua l) assessment. STUDY DESIGN: We conducted pelvic examinations of 1004 women seeking contra ceptive services at two health centers in Baltimore. After application of a cetic acid, clinicians estimated the relative area of ectopia by visual ins pection and took cervical photographs. Two independent raters measured the absolute and relative areas of ectopia from the digitized images by means o f an analytic software program. Agreement levels between raters, between mu ltiple readings by the same rater, and between the two measurement methods were quantified by means of the intraclass correlation coefficient and weig hted kappa. RESULTS: Intrarater agreement was excellent for computer planimetry measure ments of the absolute (intraclass correlation coefficient, 0.97) and relati ve (intraclass correlation coefficient, 0.89) areas of ectopia. Interrater agreement was also high for computer planimetry measurements of the absolut e (intraclass correlation coefficient, 0.83) and relative (intraclass corre lation coefficient, 0.85) areas of ectopia. Agreement levels were moderate between clinician assessment and computer planimetry measurements of the re lative area of ectopia (kappa = 0.48), but agreement was better when clinic al assessment was limited to observations by a single, experienced clinicia n. CONCLUSION: Measurement of cervical ectopia by computer planimetry was high ly reliable and appears appropriate for assessment of the role of ectopia i n the acquisition of cervical infections. Clinical assessment of cervical e ctopia may be used when computer planimetry is not available.