Extraneous Variables
Extraneous variables are those that, being undesirable and, in many cases, unpredicted, still produce an impact on the results of an experiment since they change the relationship between the variables in which the researcher is interested. Thus, these factors cannot be ignored as they may distort the interpretation of the final results, introducing error into the experiment. That is why it is highly important to identify extraneous variables, minimize their presence, and control the effects they produce on the outcome of the research (Grove, Burns, & Gray, 2014).
The current research question is as follows: “In Hispanic patients with gastric cancer, does the prevalence of chemotherapy-induced nausea and vomiting differ in patients treated with conventional medicine compared to patients who receive herbal treatment in the form of ginger?” Thus, the related, extraneous variables could be:
- Investigator effects: the researcher’s personal views that may influence the attitudes of the patients to the interventions (e.g., if the researcher were to show a positive or negative attitude to the conventional or herbal treatment, it might affect the results of the questionnaire since some participants could be suggestible);
- Demand characteristics: environmental factors that may affect the outcome of the experiment (e.g., the conditions of patient care may be drastically different, which implies that the patients’ reactions to each type of treatment are likely to be predetermined by the quality of its administration);
- Participant variables: the personal background of each participant (e.g., their background knowledge regarding both treatment methods, their health statuses, different levels of intensity and occurrence of nausea, and even their beliefs in either traditional or alternative methods of medical intervention may influence the findings); and
- Situational variables: environmental factors that may affect the results (e.g., light, noise, smell, fasting, and other physical factors that may provoke or aggravate nausea and vomiting).
Instruments
To ensure an accurate estimation of results, two instruments will be implemented: a patient record survey and the Functional Assessment of Cancer Therapy (FACT). The types of measures taken will include magnitude, duration, occurrence, and severity.
The first instrument will make it possible to collect background information that has a higher degree of validity and reliability than patient-reported information, as supported by evidence. It has been estimated that the review of medical records has a high level of reliability; indeed, in 93% of cases, patients’ records correctly indicated the presence or absence of adverse factors. However, in 84% of cases, nurses agreed that the second stage of research with other instruments was required. The validity of the instrument, according to different estimates, varies from 72% to 94% (Macharia et al., 2016).
Thus, the use of medical records as the sole source of data will not be sufficient for an objective evaluation of vomiting connected with cancer-related therapy. To supplement medical records, FACT offers the most suitable patient-reported outcome measure in the form of a questionnaire that assesses four aspects of the impact of both conventional and herbal treatments: physical, emotional, functional, and social. The tool has 27 questions on a 5-point scale (0-4), in which higher numbers indicate a better state. FACT scores have been proven to have a Cronbach’s α of 0.8 or above, which shows perfect reliability while at the same time having good construct validity (Zhou et al., 2012).
If a new questionnaire is generated during the study, its validity will be tested by a panel of experts and by a measure of its correlation coefficient. In contrast, its reliability will be determined by the reliability coefficient.
Description of the Intervention
The proposed research is expected to include a sample of approximately fifty people selected from three different hospitals located in the LA area: the LAC Medical Center, the Norris Comprehensive Cancer Center, and the Keck Medical Center. The participants will be divided into control and intervention groups, one of which will receive the conventional medicine for treating chemotherapy-induced nausea and vomiting, and the other of which will receive an herbal treatment based on ginger. This intervention was chosen because there is evidence that ginger is capable of reducing the severity of nausea and vomiting that some medications and therapies may provoke.
However, it requires more profound research as ginger is also reported to have such side effects as rash, flushing, itching, heartburn, and bruising in some patients (especially in children). Furthermore, the herbal treatment of chemotherapy-induced nausea has always been tested only in combination with conventional medications (Bossi et al., 2016). This study will test its effectiveness when implemented exclusively.
Data Collection Procedures
The collection of data from medical records will be completed as follows:
- Finding and analyzing data from source documents and multiple notes made by physicians;
- Making sure that diagnostic reports correspond to the patient and checking documents for errors;
- Checking the availability of all required information;
- Discussing the results with the physician to ensure correctness;
- Sending FACT questionnaires to both the control and the intervention groups;
- Assessing the scores obtained;
- Comparing the results with the ones found during the review of medical records;
- Repeating the test after the intervention is implemented and comparing the results to assess the effectiveness of each treatment method.
References
Bossi, P., Cortinovis, D., Cossu Rocca, M., Roila, F., Seminara, P., Fabi, A.,… Macchi, F. (2016). Searching for evidence to support the use of ginger in the prevention of chemotherapy-induced nausea and vomiting. The Journal of Alternative and Complementary Medicine, 22(6), 486-488. Web.
Grove, S. K., Burns, N., & Gray, J. (2014). Understanding nursing research: Building an evidence-based practice. Amsterdam, Netherlands: Elsevier Health Sciences. Web.
Macharia, W. M., Muteshi, C. M., Wanyonyi, S. Z., Mukaindo, A. M., Ismail, A., Ekea, H.,… Ngugi, A. K. (2016). Comparison of the prevalence and characteristics of inpatient adverse events using medical records review and incident reporting. South African Medical Journal, 106(10), 1021-1036. Web.
Zhou, H. J., So, J. B., Yong, W. P., Luo, N., Zhu, F., Naidoo, N.,… Yeoh, K. G. (2012). Validation of the functional assessment of cancer therapy-gastric module for the Chinese population. Health and Quality of Life Outcomes, 10(1), 145-153. Web.