Geographical variations in the sampling quality of cervical smears.

It is generally accepted that cervical smears are adequately sampled when they contain endocervical and/or metaplastic cells. An extensive literature search via MEDLINE and FAMLI for papers on cervical smears yielded 33 articles providing explicit information both on the country where the study was executed and on the relationship between the adequate sampling of smears and the sampling method used. The correlation between the geographic origin of cervical smears and the proportion of those smears that were adequately sampled was examined. The results were controlled for the sampling method. It was found that the proportion of adequately sampled smears reported in studies in the U.K. is exceedingly low, in contrast with the proportion reported from The Netherlands. The differences between the various countries studied are stable over different sampling methods. It is suggested that, in order to ameliorate the sampling quality of cervical smears, factors associated with the working conditions in particular regions also need be considered.