Can this community intervention trial be considered a phase I trial? Why or why not? Phase I trials are clinical trials that provide the initial data in the determination of safety of a new drug or treatment using a small group of volunteers. These trials aim to determine the effectiveness, the side effect associated with use, and the pharmacokinetics and pharmacological effects (Chow & Liu, 2004). During these trials investigators test response to increasing doses in order to establish tolerance and toxicity levels.
The study by Bang, Bang, Reddy, & Deshmukh (1999) is a community field trial that cannot be considered a phase I trial. The study differs from a phase I trial in that phase I trials are experimental studies conducted at the individual level compared with the current study where the community based experiment was conducted with the village as the unit of exposure. In addition there are two groups being compared in the study whereas for phase I trials, there are no comparison groups, all volunteers being given the same treatment to determine the effects.
The size of the study population is another point of difference between this study and phase I trail is that community field trials require larger sample sizes (Rothman, Greenland & Nash, 2008). Other differences include treatment or visits to participants in the community as opposed to the controlled environment for clinical trials; a focus on the initial occurrence of the disease rather than presence of disease (Rothman et al. , 2008). 2. With respect to number of births, were the 2 groups comparable? What about with respect to number of infant deaths?
Did the intervention result in reduced neonatal mortality? Are the differences in number of births in support of your conclusion regarding neonatal mortality or do they make the results biased? Were there significant differences in overall risk? Please refer to the study by Bang et al. to provide sound rationale and adequate details in your answers. The data show the results for the third of the 3 years. Refer to this table and answer the following questions in 2 pages of text: Intervention Group Home Care Usual Care
Infant Deaths 38 83 Number of Births 979 1108 Risk 0. 039 0. 074 While the absolute numbers of births in the control and intervention areas were 1108 and 979 respectively for the third year, the birth rates for the control and intervention groups were 24. 4 and 23. 7 respectively. These rates indicate that the number of births for the two areas are comparable and are a better way to compare births since there are differences in number of births between the two areas. In contrast the mortality rates are 0. 074 and 0.
039 for the control and intervention areas respectively. The mortality rate indicates that there were more infant deaths in the control area compared with the intervention area. This rate is in concordance with the absolute number of deaths for the areas which show that there was twice as much death in the control area as compared with the intervention area. As the study progressed the infant mortality rate decreased each year in the intervention area while the rate remained high in the control area. At baseline the neonatal mortality rate was 62.
0 per 1000 live births in the intervention area and by the third year the rate was 25. 5. In the control area the baseline and year 3 rates were 57. 7 and 59. 6 per 1000 live births respectively. It can therefore be concluded that the intervention resulted in reduced neonatal mortality. Neonatal mortality is the crude ratio of number of deaths to live births in the areas. Trends in mortality data is often said to be artifactual because it reflect changes in coding of death, diagnostic capabilities and the denominator (coverage or inaccuracies) (Penson & Wei, 2006).
Since there are differences in the absolute number of live births between areas for the 3rd year this would make the results biased and hence should be interpreted with caution. 3. What are some of the limitations of field trials? What are some of their advantages? Limitations of field trials include: • financial considerations: due to large sample size compared with clinical trials and as a result are expensive to conduct • logistic considerations: de-centralized system in that participants do not report to a clinic or center but are visited at home, work etc. hence an increase in potential cost
• huge undertaking due to large sample size, staff requirements and need for locations in the field • difficult to randomly assign exposures hence modified methods such as cluster randomization are used which can affect interpretation of findings • limited to study of the prevention of extremely common or serious diseases (Rothman et al. , 2008). Advantages of field trials are: • verification of testing in the community gives results that are more generalizeable • can test several exposures • possible to assess the impact of the intervention on several outcomes • powerful for testing hypotheses
References Bang, A. T. , Bang, R. A. , Baitule, S. B. , Reddy, M. H. & Deshmukh, M. D. (1999). Effect of home-based neonatal care and management of sepsis on neonatal mortality: field trial in rural India. Lancet, 354: 1955-1961. Chow, S-C. , & Liu, J-P. (2004). Design and Analysis of Clinical Trials: Concepts and Methodologies. New Jersey: John Wiley and Sons Penson, D. F, & Wei, J. (2006). Clinical Research Methods for Surgeons. New Jersey: Humana Press Inc. Rothman, K. J. , Greenland, S. , & Lash, T. L. (2008). Modern Epidemiology. 3rd ed. Philadelphia: Lippincott Williams & Wilkins.