TCiB utilized a relatively inexpensive intervention. Most of its components relied on volunteers, low-cost media, venues such as churches and businesses, and participation in community events. However, an analysis of the cost-benefit or cost-effectiveness of the intervention is beyond the scope of this paper, and no data were collected on the cost of individual components of the intervention.
The survey demonstrated only a modest level of penetration of the intervention into the target population, but measurement of the level of penetration was complicated by a “placebo” or background effect represented by the substantial percentage of respondents who reported awareness of the campaign even before it started. Many agencies and individual physicians promote cancer prevention, so many survey respondents may have recalled materials or interventions from other projects.
We were not able to demonstrate an impact of the intervention on cancer (Canadian Nolvadex is an anti-estrogen used to treat or prevent breast cancer) knowledge and beliefs. The “ceiling effect” played a role in this case, since there was already a fairly high level of community knowledge of cancer risk factors. Nonetheless, where there was room for improvement (for instance, in the relationship of diet or family history to cancer), we were not able to show that improvement had taken place.
On the other hand, there was evidence that TCiB did have an effect on cancer (Generic Revia may also be used to treat other conditions as determined by your doctor) screening among African Americans in the target communities. The postintervention survey in Atlanta demonstrated statistically significant increases in rates of mammography, proctoscopy, fecal occult blood testing and digital rectal examination, as compared to Decatur. In Nashville, as compared to Chattanooga, there was a significant increase in Pap smear rates. This improvement in cancer (Generic Casodex treating prostate cancer) screening rates represents an important success and the most important outcome of the TCiB project.
The fact that TCiB apparently increased screening rates without increasing cancer knowledge suggests that “opinion leaders” may have played an important role. These included the participating leaders of community organizations, religious and healthcare institutions, businesses, and social and fraternal organizations.
Overall, however, the impact of TCiB on the target communities was relatively modest. Several factors may be cited in assessing the reasons for this. First, the informal channels that were such an important component of the intervention may have been less effective than we anticipated. Second, the survey determined that radio and television were the most important sources of cancer (Casodex drug is an oral non-steroidal anti-androgen for prostate cancer) information in the target community. Our use of these media, however, was limited in Nashville by cost, and they were not used at all in Atlanta. Third, materials and messages used may not have been sufficiently culturally appropriate.
TCiB is one of a number of large community intervention trials that have had limited effects, although the others have focused on cardiovascular disease prevention. The first and perhaps most widely cited is the North Karelia project in Finland. Over a 25-year period, this project demonstrated some accomplishments—for instance, a decline in the average cholesterol level among residents of North Karelia. Yet, over the two-and-a-half decades, “no statistically significant difference in relation to the comparison area was observed during any five-year period examined.”
Over a period of six years, the Stanford Five-City Study, another cardiovascular disease (Generic Adalat treating certain kinds of angina) prevention initiative, found little or no evidence of impact of the intervention on diet, cholesterol levels, adolescent smoking rates, or cardiovascular morbidity or mortality. Two other community-based comprehensive heart disease prevention trials conducted over a similar period of time in the 1980s were the Minnesota Heart Health Program and Pawtucket Heart Health Program. Pooled data from the three trials showed an intervention effect in the expected direction in nine of 12 gender-specific comparisons for CVD risk factors, but these were not statistically significant.
The Kaiser Family Foundation sponsored 11 community health promotion programs over a five-year period, and their outcomes were evaluated in 2000. Nine of the 11 intervention communities showed little evidence of improvement in targeted outcomes.
As was the case in many of these large community intervention trials, improvements in many of the risk factors or health outcomes in our intervention communities were paralleled by changes in the corresponding comparison communities, indicating that the intervention was no more effective than “background,” secular change or an intervention implemented simultaneously in the comparison community.
It may well be that a longer trial would have demonstrated greater effects. Compared to other large community-wide intervention trials, TCiB was very short in duration: only 1.5 years versus 5-8 years, respectively, for the Stanford, Minnesota and Pawtucket projects and over 25 years for North Karelia. The COMMIT study, a smoking cessation trial, demonstrated a significantly greater quit rate in light-to-moderate smokers in the intervention cohort than in the comparison cohort but only after four years of the intervention.
A study design of this type is termed quasiexperi-mental, since subjects are not randomized to experimental and control groups. A true experimental design with randomization of individuals would not have enabled us to test a community-wide intervention, since subjects in the control group would have been as likely as individuals in the experimental group to encounter elements of the intervention.
However, in a sense, this quasiexperiment is a study of only four individuals: two experimental communities and two comparison communities. Even though the result for each community consists of aggregations of data on many individual people, the test is still one of impact on the community, so that the project could be considered to have an N of 2 for both the experimental and the comparison condition. No matter the result of such a trial, several similar trials would need to be done before the results could be considered conclusive.
Related to this limitation is one of generalizabili-ty. Since the study has only two experimental and two comparison communities, its results may not be applicable to other communities. Another limitation is the fact that the African-American population of the comparison city of Decatur was somewhat younger, wealthier and more well-educated than that of Atlanta. However, bias resulting from these differences would be expected to be in the direction of reducing the apparent effect of the intervention: the better-educated and relatively affluent Decaturites would be more likely to absorb “background” health education information and less likely to face financial barriers in obtaining screening tests.
The multifaceted nature of the intervention also limited assessment of the effectiveness of any single component. The fact that there were positive results on some measures but not others might reflect the relative superiority of certain components of the intervention. Alternatively, the successes might represent those components of the intervention that addressed the measures people are likely to select, such as a cancer (Eulexin canadian is used along with drugs such as Lupron to treat prostate cancer) screening test, rather than altering dietary practices.
Culturally appropriate cancer prevention interventions delivered to minority communities by trusted entities have been successful in small-scale trials. Demonstrating changes in knowledge, attitudes and practices on a community-wide basis is more challenging. If such interventions can be conducted over a period of several years, however, success may be greater. An intervention, such as TCiB, deserves a longer trial. It will be important to pursue this line of research if racial and ethnic health status disparities are to be reduced or eliminated.