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Biomedical subjects

C A Waddell

Publications and source records attributed to C A Waddell.

8 recordsLinked to original sources
PubMed1998

A case-control study of true-positive versus false-negative cervical smears in women with cervical intraepithelial neoplasia (CIN) III.

Cervical smears (n = 150) from five departments showing high-grade dyskaryosis were examined by three cytologists. All the smears came from patients with biopsy-proven CIN III. One hundred had been correctly reported (true positives) but 50 had originally been reported as negative and had been found to be positive only on review (false negatives). There were significant differences between the two sets in the characteristics of the dyskaryotic cell population. The false-negative smears tended to have fewer than 200 dyskaryotic cells. The nuclei of the dyskaryotic cells tended to have fine rather than coarse nuclear chromatin. A smear with fewer than 50 dyskaryotic cells is 26 times more likely to be reported as negative than one with more than 200 dyskaryotic cells. The results suggest that there is a type of severely dyskaryotic smear that is inherently likely to be missed on routine screening.

Case-Control Studies↗
PubMed1997

The influence of the cervix on smear quality. I: Atrophy. An audit of cervical smears taken post-colposcopic management of intraepithelial neoplasia.

Out of 951 smears taken from women attending a hospital cytology clinic, 122 were found to be of poor quality. Twenty-eight percent of these were associated with clinical and/or cytological atrophy, and in 91% of these the main adverse factor affecting smear quality was scantiness. The relative risk of obtaining a scanty smear was found to be 4.8 times greater in women in whom clinical atrophy was identified when compared with those with no atrophy. It is suggested that a reduction in the number of scanty, and hence potentially inadequate, smears in the screening programme may be achieved by the use of more appropriate sampling implements in all women in whom there is clinical evidence of atrophy. Further review of alternative sampling methods is indicated.

Adult↗
PubMed1990

The Cervex: an ectocervical brush sampler.

The performance of a new ectocervical brush sampler--the Cervex--was compared with the Ayre spatula in 280 paired cervical smears. The Cervex smears were superior in quality of spread, transformation zone sampling in all degrees of cervical patency and in detection of histologically proven epithelial abnormalities, with a false negative rate of 10.9% compared with 20% for the Ayre. Improvement in predictive value was noted in atrophic samples, with increased cellularity and transformation zone representation. Difficulty has been encountered in obtaining adequate samples from the older woman and from those with iatrogenic scarring of the cervix. Although two-sampler techniques may be used, submission of high quality pan-cervical material from a single sampler onto one slide is economically and organizationally attractive. The Cervex seems capable of producing such samples and deserves further evaluation for routine screening.

Adolescent↗