Study's Statistical Conclusion And Internal Validity example essay topic

According to the CDC, the majority of female adolescents will have had at least one sexual partner by the time they reach the age of 18. Once reserved for high school students, sex ed is now being introduced in junior high and even elementary schools. It is undeniable that our teenagers are becoming sexually active earlier and inevitably, are vulnerable to sexually transmitted infections and HIV. While it is impossible to alter the choices of sexually active teens once they have been made, it is a mandate for those who interact with them to equip teens with the proper resources to make smart choices and offer suggestions to modify risky behavior.

The aim of this particular study was two-fold. First, the authors studied the possibility and practicality of reducing the HIV risk among adolescent girls through the utilization of a small group, community-based setting. Secondly, the effectiveness and usefulness of such an intervention was determined and further analyzed using a controlled design. In the examination of statistical conclusion validity pertaining to this study, one threat that is imperative for the reader to consider lies in the low statistical power of the study. With 129 girls recruited, less than half (62) attended either the HIV or control intervention groups with only 48 completing the three month follow up session. Polit and Beck states that studies with low statistical power may not succeed in establishing a relationship between the variables.

As a pilot study, it is hardly dismissive and worth noting that, at best, a relationship may be present or could be present between the two variables, however, the low statistical power causes me to hesitate to assign an irrefutable relationship between the intervention group and reduced risk behavior as demonstrated by the behavioral changes (decreased substance abuse, increased knowledge on HIV prevention, fewer engagement in risky sexual behavior). The authors acknowledged this threat to the statistical conclusion validity but also noted that outcomes were "encouraging". Attrition presents a threat to both statistical conclusion and internal validity. In the aforementioned statistics, it is obvious to deduce that attrition was a direct result of the unavailability of many girls, which consequently resulted in low statistical power. The attrition rate in this study can be considered random as it was blamed on work schedules and inability to form contact and did not alter extraneous characteristics of those remaining in the study. The attrition rate along with selection bias that may have occurred make it difficult for me to determine a resolute causal inference between the intervention and the outcome.

The outcome could have also been influenced by the girls' desire to please the researchers, "give them what they " re looking for", or motivated by the monetary reimbursement. Again, as a pilot study in which the efficacy and feasibility of such interventions is also studied, this study can act as a catalyst to strengthen future studies of similar nature. Perhaps the most exigent validation tool in the notion of design validity, construct validity observes whether the cause in a study, when operational ized, represent what the investigator (s) say they are representing. In the discussion of confounding of constructs in which a treatment is "more than" what it is conceived to be, one potential source of confounding may that of participant expectancies. In providing a group-based setting in which discussions were facilitated, we cannot eliminate the possibility of the participants gradually viewing the "treatment" as more of a support group or safe haven for discussion of sensitive topics and for answers to urban legends or myths in relation to sexual behavior and HIV. Following this, participant expectancies are altered and may present a threat to construct validity.

In this case, altered participant expectancies can be considered an insignificant threat due to the fact that the altered participant expectancies may actually enhance or contribute to the outcome. In assessing whether an inadequate pre-experimental explication of the effect is a threat to the construct validity, I believe this study pointed towards a reasonable and plausible outcome for its treatment. While there are many opportunities to further strengthen the study's statistical conclusion and internal validity, the effect of the treatment was appropriate and did not present a threat to the study's construct validity. The external validity of a study is looked upon to evaluate whether the findings can be generalized to other situations and populations. This study was fashioned after a study conducted by Casey et al., 2000 in which African American women were also randomized to HIV risk reduction or a control group.

Our study included girls aged 15-19 with 59% whites, 29% blacks, 10% Hispanic, and 2% Asian whom were all sexually active. The study cannot represent male adolescents nor can it be generalized to include adolescents from rural or suburban environments. The representation of this study can be considered generalizable to other urban populations, however, because of the small number of subjects, the external validity is not considered to be solid. This follows Polit and Beck's argument that it is impossible for a study to be externally valid if internal validity is lacking. The study's threat to validity could have been decreased through the careful retention of study subjects through follow-up phone calls or emails and also through the initial recruitment of more study subjects.

Extensive recruitment for a larger sample size is also held to practical limitations of manpower and finances. If the researchers had chosen to extend the longitudinal aspect of this study design with a follow up study say, one year down the road, the lifestyle and behavioral change or retention of education received could therefore be studied and taken into account. The limitations of a follow up study one year down the road in addition to the three month follow up is that an even higher rate of attrition can be expected. The authors were relatively successful in this pilot study in that despite the low statistical power and high attrition rate, the study proved the feasibility and efficacy of the intervention and pioneered a path for future evaluations and studies (with larger samples) to reduce HIV risk among the vulnerable.

The authors qualified their findings adequately by being realistic and willing to acknowledge the limitations and inadequacies of their study. In conclusion, this was a significant pilot study for educators and healthcare workers alike who seek to create new and effective methods of reducing the risk of HIV and changing sexual lifestyles among teens. Extending beyond just sexual education, this study attests that teens enjoyed the ability to express their concerns and to have misconceptions clarified about HIV risk and other sexuality issues that are not addressed at school or through parents. This study can benefit from further research and evaluation.

National Center for Chronic Disease Prevention and Health Promotion: Healthy Youth! (n. d. ). Retrieved June 28, 2005 from web.