2. A study examined the death rates from cervical cancer in each of the 50 US states in
relation to the average percentage of women in each state undergoing annual PAP sm
screening. What type of epidemiological design is this?
Answers
Explanation:
Cervical Cancer Prevention - Cervical Screening: Science in Evolution
Mahboobeh Safaeian, PhD, MPH and Diane Solomon, MD
Additional article information
Cervical Cancer Burden
Worldwide, there were approximately 493,243 new cases, and 273,505 deaths attributed to cervical cancer in 2002, which is about one-tenth of total female cancer deaths 1. Cervical cancer incidence 2, and mortality in the United States has declined significantly since the 1950's by more than 70% 3,4. This decline is mainly attributed to the introduction of the Papanicolaou test in the 1940's. Cervical cancer which in this country was the number one killer of women, is now ranked 12th in cancer deaths for women in the US 5,6. In the US, it is estimated that 11,150 women will be diagnosed with cervical cancer, and approximately 3,670 will die of it. However, cervical cancer is the second most frequent of all female malignancies worldwide, with 80% of the cases occurring in resource-poor countries 7. While in the United States and most developed countries, cervical cancer accounts for 7% of all female malignancies, in developing countries, it accounts for 24% of all such cancers 1. This disparity is primarily attributed to the lack of screening and treatment of pre-cancerous lesions 1.
The anatomical accessibility of the cervix to direct examination, with a long preclinical stage during which precursor lesions can be treated conservatively and successfully (∼95%) 8, make cervical neoplasia ideal for secondary prevention efforts such as screening. The Pap smear test is probably the most widely used cancer screening test, even though it has never been evaluated in a randomized controlled trial, and will not be because it is been accepted as an effective screening tool. Additionally there are numerous convincing epidemiological data which show that since the introduction of Pap in countries with well organized screening programs, and with wide population coverage, both incidence of, and mortality from cervical cancer has significantly decreased. The best data to support these observations come from Nordic countries. Incidence of cervical cancer has fallen by more than 50% in Finland, Sweden, Denmark, and Iceland, where organized cervical screening programs were established in the 1960s 9. Interestingly, despite the availability of a Pap screening program in England, cervical cancer incidence remained relatively constant, until the introduction of an organized screening program in 1988, which led to a dramatic reduction in subsequent years 9.