Instruments used in measuring symptoms, health status and quality of life in hypothyroidism: a systematic qualitative review

Abstract

Symptoms of hypothyroidism are varied and nonspecific, thereby making clinical diagnosis impossible. Some patients report ongoing symptoms despite treatment. Measuring symptoms, health status and quality of life by using appropriate instruments, in addition to biochemical tests, is therefore vital to quantify disease severity and assess response to treatment. A number of instruments have been used in hypothyroidism, leading to lack of clarity about what exactly is being measured, and the rationale for the inclusion of particular measures is often uncertain. To evaluate and compare instruments used in hypothyroidism in assessing patient-reported outcomes. All published literature on MEDLINE until March 2005 was searched using the keywords 'hypothyroidism', 'symptoms', 'quality of life' and 'health status'. Articles reporting controlled trials or instrument design and development were analysed to assess the instruments used and to ascertain whether they were measuring the stated outcome. Available tools to measure symptoms, health status and quality of life in diagnosis and management of hypothyroidism are discussed. We also describe how these tools have been described in published clinical trials along with the advantages and possible pitfalls of each of the commonly used tools. Some instruments reviewed have not been suited to the outcome being studied, thereby giving rise to questionable results. This review should be useful for clinicians, researchers and patient-support groups in understanding the principles behind these tools and the results obtained from their use in clinical practice, and in selecting measures for their own use.