Introduction
Hospitalized older adults are a vulnerable population with an increased risk of developing delirium, a serious and potentially preventable condition. Delirium is characterized by acute confusion, disorientation, and altered consciousness. It is associated with numerous adverse outcomes, including prolonged hospital stays, increased morbidity and mortality, and long-term cognitive impairment. This essay aims to explore the efficacy of non-pharmacological interventions in reducing the incidence of delirium in hospitalized older adults. We will discuss the appropriate research design, sampling strategies, survey development, and address threats to internal and external validity.
Sampling Strategies
Two sampling strategies that could be used to recruit hospitalized older adults into a study on non-pharmacological interventions for preventing delirium are convenience sampling and stratified random sampling.
Convenience Sampling: Convenience sampling involves selecting participants based on their easy accessibility and availability (Gravetter & Forzano, 2018). This strategy is convenient and less time-consuming, making it suitable for initial exploratory studies. Researchers could recruit older adults from specific hospital units or wards, making it easier to access potential participants. However, convenience sampling may lead to biased results since it does not provide a representative sample of the entire population of interest. For instance, individuals with less severe delirium or who are more cooperative may be overrepresented.
Stratified Random Sampling: Stratified random sampling involves dividing the population into distinct subgroups (strata) based on specific characteristics and then randomly selecting participants from each stratum (Gravetter & Forzano, 2018). In this case, the subgroups could be based on age, gender, or severity of illness. Stratified random sampling ensures better representation of the population and reduces the risk of bias. However, it may require more time and resources to identify and recruit participants from various strata.
Survey Development and Psychometric Properties
To assess the efficacy of non-pharmacological interventions in preventing delirium, a short survey can be developed with four items:
Have you received any non-pharmacological interventions during your hospital stay? (Yes/No)
If yes, please specify the types of interventions you received. (Open-ended response)
On a scale of 1 to 10, how satisfied are you with the non-pharmacological interventions you received? (1 = Not satisfied, 10 = Very satisfied)
Have you experienced any delirium-related symptoms during your hospital stay? (Yes/No)
Psychometric Properties: Ensuring the Reliability and Validity of the Survey
Developing a reliable and valid survey is crucial for accurately measuring the efficacy of non-pharmacological interventions in preventing delirium among hospitalized older adults. Psychometric properties are statistical measures used to assess the quality and performance of a survey. In this section, we will discuss the three key psychometric properties of the survey – content validity, internal reliability, and test-retest reliability – and their importance in ensuring the robustness of the data collected.
Content Validity: Ensuring Survey Relevance and Comprehensiveness
Content validity refers to the extent to which the survey items adequately represent the construct being measured (Devellis, 2017). In the context of our survey, content validity ensures that the questions accurately capture the various aspects of non-pharmacological interventions for delirium prevention in older adults. To establish content validity, experts in the field of delirium prevention and non-pharmacological interventions should review the survey. They can provide feedback on whether the items are relevant, comprehensive, and representative of the interventions being investigated.
Experts can also assess the clarity and appropriateness of the language used in the survey to ensure that it is understandable to the target population. Any necessary revisions can be made based on their recommendations to enhance the survey’s content validity. By ensuring content validity, researchers can confidently interpret the survey results, knowing that the items accurately measure the intended construct.
Internal Reliability: Assessing Consistency of Survey Items
Internal reliability assesses the consistency of the survey items in measuring the same construct (DeVellis, 2017). In the context of our survey, internal reliability ensures that the questions consistently capture the participants’ perceptions of the non-pharmacological interventions received during their hospital stay. To test internal reliability, the survey can be administered to a pilot sample of hospitalized older adults.
Researchers can then calculate the Cronbach’s alpha coefficient, a widely used measure of internal reliability. The Cronbach’s alpha coefficient ranges from 0 to 1, with higher values indicating stronger internal consistency among the survey items. A value above 0.7 is generally considered acceptable for research purposes (DeVellis, 2017).
A high Cronbach’s alpha indicates that the survey items are measuring the same underlying construct consistently, providing confidence in the reliability of the data collected. If the internal reliability is low, researchers may need to reconsider or revise certain survey items to improve the consistency of the responses obtained.
Test-Retest Reliability: Ensuring Stability of Survey Responses
Test-retest reliability evaluates the stability of the survey over time (DeVellis, 2017). In the context of our survey, test-retest reliability assesses whether participants’ responses remain consistent when they complete the survey on two separate occasions. A subsample of participants can be asked to complete the survey at two different time points, with a reasonable time interval between administrations.
The responses from both occasions can then be compared using correlation analysis. A high correlation coefficient indicates good test-retest reliability, suggesting that the survey is producing consistent results over time. This property is particularly important for surveys administered to a population with cognitive impairments, such as older adults, as it ensures that their responses are not influenced by transient factors.
Threat to Internal Validity: Maturation Effect – Mitigating Natural Changes
One significant threat to internal validity is the maturation effect, where changes in participants’ outcomes occur naturally over time, unrelated to the interventions being studied (Gravetter & Forzano, 2018). In the context of delirium prevention, older adults may experience fluctuations in their cognitive status during their hospital stay due to the aging process or the progression of their underlying medical conditions. Such changes could confound the assessment of the efficacy of non-pharmacological interventions.
To address this threat, researchers should implement a control group in the study design (Gravetter & Forzano, 2018). The control group should receive standard care without any additional non-pharmacological interventions. By comparing the outcomes of the intervention group to those of the control group, researchers can isolate the effects of the non-pharmacological interventions from the natural changes that may occur over time. Additionally, random assignment of participants to the intervention and control groups can help ensure that both groups are comparable at baseline, minimizing the impact of potential confounding variables (Gravetter & Forzano, 2018).
Threat to External Validity: Selection Bias – Ensuring Representative Sampling
Selection bias is a potential threat to external validity, occurring when the sample of participants chosen for the study does not accurately represent the broader population of interest (Gravetter & Forzano, 2018). In the case of our study on hospitalized older adults, selection bias could arise if the participants selected for the research are not representative of all older adults admitted to hospitals.
To minimize selection bias and enhance external validity, researchers should employ a robust sampling strategy, such as stratified random sampling (Gravetter & Forzano, 2018). Stratified random sampling involves dividing the target population into subgroups (strata) based on relevant characteristics, such as age, gender, or severity of illness. Then, participants are randomly selected from each stratum. This method ensures that each stratum is proportionally represented in the sample, leading to a more diverse and representative study population.
Additionally, researchers should strive to achieve a high response rate among the selected participants to minimize non-response bias (Gravetter & Forzano, 2018). Non-response bias occurs when participants who choose not to participate in the study differ systematically from those who do participate. By implementing strategies to encourage participation and follow up with non-respondents, researchers can increase the likelihood of obtaining a representative sample, thereby enhancing the external validity of the study.
Conclusion
In conclusion, non-pharmacological interventions have shown promise in reducing the incidence of delirium in hospitalized older adults. A randomized controlled trial with appropriate sampling strategies, reliable surveys, and attention to threats to internal and external validity will provide valuable insights into the efficacy of these interventions. Future research should continue to explore different non-pharmacological approaches to optimize delirium prevention in this vulnerable population.
References
Devellis, R. F. (2017). Scale Development: Theory and Applications (4th ed.). Sage Publications.
Gravetter, F. J., & Forzano, L. B. (2018). Research Methods for the Behavioral Sciences (6th ed.). Cengage Learning.
