Background

Thyroid diseases are frequent. They include both metabolic changes and gland enlargement (goitre). Previous research and clinical suspicion indicate that the life quality of many patients is reduced despite successful treatment. Research methods are, however, weak, and especially a well-tested, disease specific life quality questionnaire is needed. Several treatment possibilities exist for the each thyroid disease. For example, hypermetabolism can be treated with either medication, radioactive iodine or by surgery. No comparative studies of life quality using the different treatment modalities exist.

Purpose

To develop and evaluate a questionnaire to measure health-realted life quality in patients suffering from thyroid diseases.

Methods

To ensure that all relevant aspects are included, the questionnaire will be developed on the basis of a systematic examination of the scientific literature and interviews with 13 physicians and 100 patients. The questionnaire will then be tested by 100 new patients. After revision, the questionnaire will be answered by 1000 patients with a view to scientifically investigate the measuring capacity of the questionnaire. This will be done using traditional psychology methods (psychometry) as well as modern statistical methods (structural equations for categorical data and "item response" models).

Relevance

The above-mentioned questionnaire is necessary for clarifying whether these diseases reduce life quality and in the long-term whether a difference in life quality exists using the different treatment alternatives and whether treatment can be improved. It should also be included in quality protection studies, in the evaluation of new treatment modalities and possibly also in the treatment of the individual patient.

Inclusion Criteria:

All out-patient patients with benign thyroid disease.

Exclusion Criteria:

Unable to complete questionnaire: must be able to read and write Danish