(iHOT-33) International Hip Outcome Tool

June 17, 2016


International Hip Outcome Tool (iHOT-33)

In 2012, the International Hip Outcome Tool (iHOT-33) was developed by Mohtadi et al as a tool for use in younger, active patients to assess their ability to return to an active lifestyle. The developers noted that many of the existing hip PRO tools were for use in patients with hip fractures or those undergoing total hip arthroplasty. These tools often have a ceiling effect that make the tools less applicable to younger and more active populations.

The iHOT-33 is a 33-item survey with questions relating to Symptoms and Functional Limitations, Sports and Recreational Activities, Job-Related Concerns, and Lifestyle Concerns. For each question, patients are asked to mark on a visual analog scale (VAS) with the verbal anchors “no problems at all” on the far right and “significantly impaired” on the left. The total score is calculated as a simple mean of the responses ranging from 0 to 100, with 100 representing the best possible quality-of-life score.

Development of the iHOT followed a rigorous methodology that involved a large number of patients and results show that it is a valid, reliable, and highly responsive tool.

A shorter version of the International Hip Outcome Tool has also been developed, the iHOT-12. It has similar characteristics to the original iHOT-33 questionnaire and is also valid, reliable, and responsive to change. Due to its brevity, the iHOT-12 may be more appropriate for use in a clinical setting for initial assessments and post-operative follow-up.


The International Hip Outcome Tool has been validated for use in hip arthroscopy and is particularly useful in a younger, more active patient population from the ages of 18-60. A systematic evaluation of the psychometric properties of other outcome measures such as the Modified Harris Hip Score (MHHS), the Hip Outcome and Disability Survey (HOOS) and the Hip Outcome Score (HOS) revealed these tools to suffer from ceiling effects and decreased responsiveness that the iHOT-33 did not have.

Given its properties of validity, reliability, and responsiveness, the iHOT-33 has also been recommended for use as the primary outcome measure in prospective patient evaluations and randomized clinical trials.


The iHOT-33 has been criticized for the use of a composite scoring system in its survey. Using a single aggregate score instead of adopting subscales limits the tool’s ability to discriminate between important functional domains and also makes it difficult for clinicians to quickly pinpoint what specific areas patients are scoring poorly in.

Overall, the iHOT appears to be a great tool to consider when assessing outcomes and a patient’s return to an active lifestyle post arthroscopy, specifically in younger populations.

Licensing and Cost

The iHot-33 does not require a license to use. To learn more about the iHot-33, you can read their original publication here: https://pubmed.ncbi.nlm.nih.gov/22542434/.


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