'Organised' cervical screening 45 years on: How consistent are organised screening practices?

Organised screening programmes have been remarkably successful in reducing incidence and mortality from cervical cancer, while opportunistic screening varies in its effectiveness. Experts recommend that cervical screening or HPV testing be carried out only in the context of an organised programme. We sought to answer the following study questions: What does it mean for a cervical screening programme to be organised? Is there a place for opportunistic screening (in an organised programme)? We reviewed 154 peer-reviewed papers on organised and opportunistic approaches to cervical screening published between 1970 and 2014 to understand how the term 'organised' is used, formally and in practice. We found that despite broad recognition of a prescriptive definition of organisation, in practice the meaning of organisation is much less clear. Our review revealed descriptions of organised programmes that differ significantly from prescribed norms and from each other, and a variety of ways that opportunistic and organised programmes intersect. We describe the breadth of the variation in cervical cancer screening programmes and examine the relationships and overlaps between organised and opportunistic screening. Implications emerging from the review include the need to better understand the breadth of organisation in practice, the drivers and impacts of opportunistic screening and the impact of opportunistic screening on population programme outcomes. Appreciation of the complexity of cervical screening programmes will benefit both screeners and women as programmes are changed to reflect a partially vaccinated population, new evidence and new technologies.