Women have had another salutary reminder that, despite what doctors and the government like to pretend, the cervical smear test is a far from foolproof marker for cancer (see WDDTY, Vol 1 No 3).
Some 20,000 tests done over the last five years under the screening programme at the Inverclyde Royal Hospital in Scotland are to be re examined after evidence that the doctor doing the analysis may have misread the results.
On a preliminary re examination, 40 out of 1000 smears taken since 1987 were found to be "abnormal", or "inadequate" (and so require a repeat test).
The Scottish debacle is the latest in a series of such incidents.
In 1987, in Liverpool, 45,000 tests were re examined and 911 found to have been wrongly diagnosed.
In 1988, in Manchester, a batch of 3000 tests passed as clear were re analyzed and 60 found to be suspect.
Reporting the Scottish incident, the Daily Telegraph (29 April 1993) quotes a cytopathologist at St Bartholomew's Hospital in London conceding that the tests are always subjective and that even experienced cyto screeners can make mistakes.
It seems that even the government may be waking up to the dubiousness of the test.
According to Pulse (15 May 1993), it is likely to introduce cost cutting restrictions on its availability.
Around three million smear tests are estimated to be carried out each year at a total cost reckoned to be around lb100m to lb120m.
Last year, the government commissioned a report from the Cervical Screening Programme National Co-ordinating Network following criticism from the Public Accounts Committee that there was too little information on the cost effectiveness of the screening programme.
"It is clear the government is spending far too much on cervical screening considering the results we get," network member Dr Peter Sasieni, an epidemiologist and researcher at the Imperial Cancer Research Fund, is quoted as saying.