Practice recommendations
- Computer-based telecolposcopy and network telecolposcopy detected more cervical neoplasia than cervicography.
- Computer-based telecolposcopy could provide many women with greater access to expert diagnostic services.
Telemedicine enables doctors in rural areas or areas with poor medical service to consult with experts at distant locations. Telecolposcopy and cervicography both enable remote diagnoses of the cervix. The 2 methods differ in equipment, operations, image format, timeliness of consultation, and probably cost. However, these diagnostic approaches have not been compared previously. The purpose of this study was to compare the accuracy of telecolposcopy and cervicography with on-site colposcopy in the remote evaluation of women with potential cervical neoplasia.
Telecolposcopy and cervicography
Telecolposcopy involves a distant expert colposcopist’s evaluation of women with potential lower genital tract neoplasia.1 Existing telemedicine network and computer systems provide an audiovisual interface between local colposcopists and expert colposcopists at other locations.2 For health systems already using computer or video networks, telecolposcopic consultation can be implemented with only small additional charges per examination.2 Telecolposcopy services may improve health care access for women in medically underserved areas.1
Cervicography is distant evaluation of 2 photographs taken of the cervix following 5% acetic acid application.3 A special 35-mm camera is used to take these images. The end product, developed at a central processing center, resembles a low-magnification colposcopic photograph. Certified evaluators interpret these images, classifying them as negative, atypical, or positive. Cervicography is used primarily as an adjunct test to the Papanicolaou (Pap) smear.4 It has also been evaluated as an intermediate triage test for evaluating women with mildly abnormal Pap smear results.5-8
Methods
Women aged 18 years or older who came to 1 of 2 rural clinic sites for a colposcopic examination were enrolled in the trial after signing an institutional review board–approved informed consent document. We included women with a recent abnormal Pap smear report or a lower genital tract finding that required further evaluation by colposcopy. The exclusion criteria were pregnancy, severe cervicitis, heavy menses, refusal to participate, or technical problems with the telecolposcopy or cervicography equipment.
Both clinics were part of the Medical College of Georgia Telemedicine Network. This system uses sophisticated telecommunications equipment to provide distant consultation services to clinicians practicing in rural areas of the state.1 Small change-coupled device cameras were attached to the colposcopes at the 2 clinics.
For network telecolposcopy, images were transmitted using the network’s existing hardware and high-speed telecommunication lines. For computer telecolposcopy, personal computers (DIMS, DenVu, Tucson, Ariz) were also used to capture and transmit images to a computer at the Telemedicine Center. These digitized images were transmitted by modem via telephone lines.2 Cerviscopes (35-mm cameras) supplied by the manufacturer (NTL Worldwide, Fenton, Mo) were used to acquire cervigrams (photographs).
Pertinent clinicians received appropriate training to take cervigrams. Certified evaluators interpreted the images according to company protocol and returned a standardized report to the investigators at a later date.
Study design
The study design has been described in detail previously.1,2 Briefly, subjects were initially examined by 1 of 3 on-site, university-based expert colposcopists, who took 2 cervigrams of each patient, and then conducted a colposcopic examination independently.
A local clinician then completed another colposcopic examination, including histologic sampling, if indicated. This examination was observed simultaneously by another expert at a telemedicine center. Prior to obtaining histologic samples or using dilute Lugol’s iodine solution, the local clinician captured 2 cervical images (low and high magnification) using the computer telemedicine system. These images were then transmitted to the expert at the telemedicine center for independent interpretation.
A third expert colposcopist interpreted the video and computer images at a later time. However, these third interpretations were not considered in this report. Colposcopists were blinded to each other’s clinical diagnoses. However, all colposcopists were informed of the subject’s referral cervical cytology results and other pertinent history.
Data analysis
Each subject had 2 observations using each of the 3 colposcopy methods (on-site, network, and computer-based), and a single observation using cervicography. On-site colposcopy, consisting of the observations of the on-site expert and local colposcopist, was considered for reference purposes. Agreement with histologic results was calculated for each method, across all histologic diagnoses together and separately by diagnosis.
Sensitivity and specificity estimates were calculated using 2 definitions of disease: (1) normal versus any other histologic diagnosis, and (2) normal or cervical intraepithelial neoplasia 1 (CIN 1) versus any more severe diagnosis. The primary analysis model was complete block analysis of variance, with subjects included as blocks in the analysis to account for the multiple observations on the same subjects. Nonparametric comparisons of proportions of agreement with histology, sensitivity, and specificity among the methods were made using permutation tests. Post-hoc comparisons were made using a Tukey test; 95% confidence intervals (CIs) were calculated for all point estimates. Adjustment for dependence among multiple observations per subject was made by basing these tests and CIs on least-squares means.