Validity and Reliability in Quantitative Studies

The validity and reliability of a questionnaire measure are essential components in quantitative studies, particularly when it comes to assessing patients' adherence to medications. In this article, we will discuss the importance of these two concepts and how they were established in a recent study on medication adherence.

In the study, criterion-related validity was demonstrated through the relationship between blood pressure control and medication adherence among patients with hypertension. The results showed that more adherent patients had better blood pressure control, indicating that the questionnaire measure is valid in assessing this particular aspect of medication adherence (χ2 = 4.24, df = 1, P < .01).

In addition to criterion-related validity, internal reliability was also established through Cronbach's alpha coefficient, which ranged from 0.67 to 0.89 across all patient groups. Test-retest reliability was assessed using Pearson's r and resulted in a high correlation of 0.97 among patients with hypertension.

The study demonstrated acceptable reliability (internal and test-retest) and validity (criterion-related and construct validity) in the patient groups evaluated. The evaluation consisted of internal reliability, test-retest reliability, criterion-related validity, and construct validity.

The Medication Adherence Report Scale (MARS-5) was used to assess medication adherence among patients with hypertension, asthma, or diabetes. The study aimed to establish the psychometric properties of this questionnaire measure and determine its usefulness in various clinical samples.

In conclusion, the validity and reliability of a questionnaire measure are crucial components in quantitative studies, particularly when assessing patients' adherence to medications. By establishing these properties, researchers can ensure the quality of their results and make informed decisions about instrument selection.

Validity and reliability in quantitative studies