Types Of Extraneous Variables : Intrinsic Variables And External Factors

Extraneous Variables

There are two types of extraneous variables: Intrinsic variables and external factors. Intrinsic variables are factors intrinsic to the subjects, such as, age, gender, and diagnosis. External factors arise from the research itself. Multiple comorbidities, such as, renal insufficiency and diabetes would be intrinsic variables that could influence the study. Patients with these conditions may be more likely to be admitted into the hospital for these conditions within thirty days of being discharged from the hospital with a primary diagnosis of congestive heart failure. This could be controlled by creating sub-groups of each population and further comparing them to each other. For example, data analysis could take the population with a primary diagnosis of congestive heart failure and a secondary diagnosis of diabetes that were provided the teach-back intervention and comparing this group with the control group with the same primary and secondary diagnosis to determine if there was a difference in 30 day readmission rates. A second extraneous variable would be age, as younger individuals might be able to retain new knowledge, and have the means of applying self-management behaviors more consistently. Randomization is the best way to control intrinsic variables. Consistent data collection and communication is an external factor that needs to be controlled. Using the same instrument, and entering data electronically will standardize data collection. While following the same teach-back format will be utilized to standardized communication.

Instrument

The Dutch Heart Failure Knowledge Scale is the tool that will be utilized to assess knowledge retention. It is a 15-item questionnaire that can be self-administered. T...

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...of each, describe signs and symptoms of worsening symptoms and what to do, and describe a low salt diet. Each item will be taught, assessed, retaught, and reassessed until clarity is established. The intervention will be conducted by a specific individual that has met proficiency in the teach-back method.

Data Collection Procedure

In this case the printed questionnaire will be given to every patient enrolled in the study prior to an education intervention. The questionnaire will be sent to the patient three days post discharge from the hospital. Since this tool can differentiate high or low knowledge, data will be entered electronically according to responses. Additionally, demographic material such as age, gender, primary and secondary diagnosis will be attached to each questionnaire. The demographic material and questionnaire will be coded for ease of data entry.