A retrospective analysis of 94 patients with CIN and false negative cervical smears taken at colposcopy

This report investigates the reasons for false negative cervical cytology in 94 out of 630 patients (15%) in whom cervical intraepithelial neoplasia (CIN) was diagnosed on colposcopically directed biopsy. Cervical smears were taken immediately before biopsy and the cases with false negative cytology were compared with those whose cytology was abnormal. Patients with false negative cytology were more likely to have been younger (P < 0.01), to have had fewer pregnancies (P < 0.001), to have had a less severe grade of dyskaryosis on their referral smear (P < 0.001), to have had no endocervical cells on the smear (P < 0.05), to have had a less severe grade of CIN on biopsy (P < 0.001), to have had no punctation visible at colposcopy (P < 0.01), and to have had no mosaic pattern seen at colposcopy (P < 0.05). We found no effect attributable to the patient's menstrual history, the interval between referral smear and colposcopy clinic visit, the smear taker or the type of spatula used to take the smear.

Reproducibility of ultrasonic measurement of fetal cardiac haemodynamics

Two observers made independent estimates of volume flow across all four heart valves in 27 fetuses using a combination of cross-sectional and Doppler echocardiography. There were considerable discrepancies between observers in volume flow estimation arising from inconsistency both in cross-sectional and in Doppler measurements. One observer also produced a second estimate by making new measurements from the original recordings. There was considerable within-observer variability which was mainly due to errors in cross-sectional measurements. The problems of applying this technique to fetal cardiac haemodynamics are discussed.