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N Dudding

Publications and source records attributed to N Dudding.

9 recordsLinked to original sources
PubMed2002

Rapid (partial) prescreening of cervical smears: the quality control method of choice?

Rapid rescreening of all negative and inadequate smears is the quality control method of choice in the UK. The sensitivity of primary screening of laboratory and individual screeners are major indicators of screening quality and are dependent on the number of false negative smears found by rapid screening for their calculation. High sensitivity may indicate good quality primary screening or poor quality rapid review. Quantifiably high quality rapid rescreening is essential if these sensitivity figures are to be meaningful. A 12-month study was undertaken in routine practice using the prescreening mode to ascertain the sensitivity of rapid (partial) screening in our department. The final results of smears were compared with those of rapid prescreening. The calculated sensitivity ranged from 92-54% for high-grade abnormalities and 75-33% for all grades, revealing a wide range of performance between individual prescreeners. Rapid prescreening can identify individuals best suited to rapid screening in routine practice. By using these prescreeners only, the sensitivity of cervical screening could be raised. Rapid (partial) prescreening should be considered as the quality control method of choice.

False Negative Reactions↗
PubMed2001

Rapid rescreen: a viable alternative to 1:10?

A rapid screen of those Pap smears designated as within normal limits is a quality control requirement of all UK laboratories. However in the United States standard QC involves a combination of 1:10 and selective rescreening procedures. Forty participants at the joint ASCT/ACP meeting in Las Vegas rapid screened 50 slides as part of a rapid screening workshop. They used different patterns of screening but were allowed only 60 seconds for each slide. Thirty of the slides contained abnormal cells but all had originally been called negative or unsatisfactory and as such were "false negatives". Ability to identify the abnormal smears varied considerably between individuals but overall rapid screening correctly identified 54% of the ascus or LGSIL cases and 61% of the HGSIL cases. The results demonstrate the superiority of such a rapid screen over 1:10 and question what if any role this outdated practice should have.

False Negative Reactions↗
PubMed2001

Rapid screening: a comparative study.

Although rapid screening of negative and inadequate cervical smears is a quality assurance requirement for all UK laboratories, there has been little attempt to standardize the method and laboratories make use of a number of different techniques and times. The aim of this study was to assess the sensitivity of these various techniques by measuring their ability to pick out known false-negative smears. Completed questionnaires from 123 laboratories across England revealed that 52% of laboratories use a "step" technique, 19% use "turret", 15% use random paths and 34% attempt to rescreen the whole slide quickly. Twenty-two percent of laboratories use a mixture of techniques. Timings are also variable, with the majority of laboratories allowing screeners to review slides at a pace decided by themselves but usually between 1 and 2 min. The study involved 120 participants who performed a total of 24 000 rapid screens. The results showed that, of the 90 abnormal slides used in the study, 62 cases (69%) were identified as abnormal or needing review by more than 50% of participants. Overall rapid screening picked out 58% of high-grade squamous abnormalities, 59% of low-grade abnormalities and 72% of glandular lesions. Step screening performed best, followed by whole slide/random and then turret. One minute was the optimum time and there was a significant fall in performance once individuals attempted to rescreen large numbers (>50). The most significant finding was the marked variation in the performance of individuals using the same slide sets.

Diagnostic Errors↗
PubMed1996

Koilocytosis; an indication for conservative management.

The management of women with mild dyskaryosis continues to be the subject of debate. The management of cases with such smears could be improved if additional morphological features were found to be indicative of low/high grade cervical intraepithelial neoplasia (CIN). Our own experience in the routine audit of the diagnostic accuracy of cervical smears had suggested that cases of dyskaryosis with koilcytosis were associated with low risk of CINIII. Two hundred and forty-four cervical smears reported as showing evidence of warty virus infection were reviewed and their subsequent histories noted. Of these smears, 173 demonstrated clear evidence of koilocytosis. Irrespective of the initial grade of dyskaryosis, only 28 cases (16.2%) had underlying CIN or had progressed to CIN over a minimum follow-up period of 21 months. Only two cases (1.2%) showed evidence of CINIII. Koilcytosis is associated with a low risk of CIN and an especially low risk of CINIII. The management of women with koilocytic smears should be modified accordingly.

Colposcopy↗
PubMed1995

Rapid rescreening of cervical smears: an improved method of quality control.

Rapid rescreening of approximately 30% of all negative and inadequate consecutive smears was carried out over a 26-month period. Smears (n = 24,012) were rescreened using a x6.3 objective only. Two minutes were allowed for each slide. Thirty-nine smears were found to have been incorrectly diagnosed as negative, a rate of 0.16%. This can be compared with the previous 26 months during which the traditional 1 in 10 random rescreening of unsatisfactory and negative smears had been carried out at a routine pace and with an objective of x10. A total of 6866 smears were rescreened. Eleven were found to have been incorrectly diagnosed as negative, a rate of 0.16%. Rapid rescreening is as sensitive as 1 in 10 rescreening, and allows a greater proportion of smears to be rescreened. We propose rapid rescreening should replace the traditional 1 in 10 rescreening methods.

False Negative Reactions↗
PubMed1987

Sensitive in situ hybridisation technique using biotin-streptavidin-polyalkaline phosphatase complex.

A sensitive in situ hybridisation technique, using a biotin-streptavidin-polyalkaline phosphatase complex detection system, was successfully applied to smears of fresh cultured cells, frozen sections, and formalin fixed paraffin processed tissue: the procedure was successful for DNA-DNA hybridizations using a variety of DNA probes. The detection method is rapid, reliable, and economical producing a purplish-blue precipitate at the site of hybridisation and clearly visible by low power light microscopy.

Alkaline Phosphatase↗