Statistics concepts and applications

Health departments react with alarm to new CDC surveillance data. (22 Jan 2009). Medical

News Today. Retrieved January 31, 2009 at http://www.medicalnewstoday.com/articles/136289.php

According to the 2009 article published by Medical News Today entitled "Health departments react with alarm to new CDC surveillance data," while the Center for Disease Control (CDC) has published alarming statistics that suggest suggesting sexually transmitted diseases (STD) in America overall have grown more prevalent, the CDC also notes that rates of certain STDs, specifically Chlamydia, have increased at an even more alarming rate. The CDC report noted that: "In 2007, more than 1.1 million Chlamydia cases were reported, which is the largest number of cases ever reported to CDC for any condition. Rates of primary and secondary (P & S) syphilis increased by 15% from 2006, and 65% of all P & S. syphilis cases were among men who have sex with men (MSM). In addition, the report shows persistent and growing racial disparities in Chlamydia, Syphilis, and Gonorrhea infections. In 2007, Blacks were 19 times more likely to become infected with Gonorrhea than whites."

However, a caution about the methodology used by the CDC must be noted regarding Chlamydia. Firstly, screening data of this illness is often taken from family planning and health clinics, which may skew the data, given that the poor, the young, and the uninsured are more apt to use such places, hence the apparent prevalence of the illness amongst minority population. Other sources of data are from similarly skewed sources as the National Job Training Program which is a "primarily a residential job training program for urban and rural economically-disadvantaged youth aged 16 to 24 years at more than 100 sites throughout the country," where "program entrants have been screened each year for Chlamydia, with all tests performed at a central contract laboratory" (STD Surveillance Report, 2007, CDC, pp. 13-14). Correctional facilities also have required STD screening programs. Disproportionate minority representation in tested populations may affect the results, and other populations, such as the older, more affluent, and Caucasian, may be underrepresented. According to the CDC statistics of the "19 million STD infections occur each year, and nearly half are among those aged 15-24 years. African-American women between 15 and 19 are particularly hard hit, accounting for the highest rates of Chlamydia and Gonorrhea of any group" (Health departments react with alarm to new CDC surveillance data," 2009, CDC). However, given the age and ethnic demographic of those who are involved in the aforementioned programs and who use family clinics rather than physicians for healthcare, this could affect the statistics. The illness may merely be spreading equally as rapidly in sectors of the population that do not utilize such sites as primary care facilities for treating issues regarding their sexual health. As of 2000, all 50 states and the District of Columbia had regulations requiring the reporting of Chlamydia cases these private physicians may be less apt to report data than social service organizations such as those reported above (STD Surveillance Report, 2007, CDC, pp. 13)

Still, the CDC suggests that family planning clinics are the most accurate places the illness. However, it admits: "Chlamydia positivity in women attending clinics is an estimate of prevalence; it is not true prevalence. Crude positivity may include those women who are tested two or more times during a single year. Comparisons of positivity with prevalence have shown that in family planning clinics, positivity is generally similar to or slightly higher than prevalence, and in STD clinics, positivity is somewhat lower than prevalence; however, these differences are usually small" STD Surveillance Report, 2007, CDC, pp. 13-15). Individuals who come to women's or STD clinics may not be representative of the population, and may be more likely to manifest prevalence of the ailment or not to manifest prevalence because of more frequent testing.

Secondly, an additional variable is that of the region-specific nature of the screening. In some regions, federally funded Chlamydia screening supplements local- and state-funded screening programs. This may make the screening more comprehensive in nature in some areas of the country than others, as in some regions there may be additional funding from local and regional as well as federal sources. The different levels of regional scrutiny may also affect the tracking of the disease, as in some regions awareness about STDs is more highly promoted in schools and in the media than other regions, which can result in higher levels of traffic at STD clinics as well as theoretically greater levels of precautions on the part of citizens. This should act as a caution that the apparent predominance of diseases in certain areas of the country may reflect a willingness upon the part of states and local authorities to devote more resources to tracking STDs.