Assessment of patients with head and neck cancer using the MD Anderson Dysphagia Inventory: Results of a study into its comprehensiveness, comprehensibility and relevance to clinical practice

Background

The MD Anderson Dysphagia Inventory (MDADI) is a widely used patient-reported outcome measure (PROM) which assesses dysphagia-related quality of life (QoL) in head and neck cancer (HNC). Despite its common use in HNC research and clinical practice, few of its psychometric properties have been reappraised since its inception. The aim of this study was to perform a survey-based qualitative analysis of UK HNC clinicians’ perceptions of the content validity of the MDADI, evaluating it across the parameters of relevance, comprehensiveness and comprehensibility as per the COSMIN guideline for PROM assessment.

Results

Four themes relating to the content validity of the MDADI were identified: (1) MDADI items lack clarity of definition of the terms ‘swallowing’, ‘eating’ and ‘dysphagia’; (2) the MDADI is perceived to be overly negative in tone including items that service users may find distressing or disempowering; (3) items in the tool are exclusory to specific subgroups of patients, such as those who are nil by mouth or socially isolated; and (4) modifications to the MDADI were suggested and encouraged to make it more clinically useful and patient-centred.

Conclusions

This study indicates that MDADI's content validity is ‘insufficient’ when rated by COSMIN parameters. This has significant implications for its continued use in HNC research and clinical practice. Further re-evaluation of the content validity of the MDADI is warranted, with potential future amendment of items being indicated if the results of this study are corroborated in subsequent research.

What this paper adds

What is already known on the subject

• The MD Anderson Dysphagia Inventory (MDADI) patient-reported outcome measure of dysphagia-related quality of life is widely used in clinical practice and international clinical trials. Content validity is considered to be the most important property of a tool when assessing its psychometric strengths and weaknesses; however, the MDADI's content validity has not been reappraised since its initial development.

What this paper adds to existing knowledge

• This study presents UK speech and language therapists’ opinions and experience of the content validity of the MDADI and this first reappraisal of its content validity since its initial development highlights several issues with this psychometric parameter of the tool. This study highlights that further re-evaluation of the content validity of the MDADI is warranted, with potential future amendment of items being indicated if the results of this study are corroborated in subsequent research.

What are the potential or actual clinical implications of this work?

• Clinicians cannot assume that commonly used outcomes tools have strong psychometric profiles. Consideration of the content validity of outcomes tools during selection for use in clinical and research practice should be key, as this will encourage use of tools that produce relevant, valid data that can contribute meaningfully to patient-centred care.