Psychometric properties of Internet-administered measures of health anxiety: An investigation of the Health Anxiety Inventory, the Illness Attitude Scales, and the Whiteley Index

•The HAI, IAS, and WI are commonly used measures of health anxiety.•Their psychometric properties have not been investigated when used over the Internet.•This study showed that they are reliable and valid in this administration format.•Internet-administration of the HAI, IAS, and WI has several advantages.•Advantages include ease of use, lowered attrition, and cost-efficient evaluation.

BackgroundThe Health Anxiety Inventory (HAI), the Illness Attitude Scales (IAS), and the Whiteley Index (WI) are three of the most widely used health anxiety measures, but their psychometric properties have not been investigated when administered via the Internet.MethodsWe investigated the three instruments' test–retest reliability, internal consistency, convergent, and discriminant validity and sensitivity to change using one sample (n = 111) of participants with severe health anxiety and one sample of healthy controls (n = 92).ResultsThe HAI, IAS, and WI showed high test–retest reliability (rs ≥ .80), good convergent, and discriminant validity and were sensitive to detect change. The HAI and IAS (αs ≥ .85), but not the WI (αs ≤ .60) demonstrated high internal consistency.ConclusionsThe HAI, IAS, and WI have good psychometric properties, except for the low internal consistency of WI, when used as Internet-administered measures of health anxiety. Using these measures over the Internet offers highly important advantages such as increased ease of administration, reduced attrition, and cost-efficient treatment evaluation.