Hypoparathyroidism Symptom Diaries Are Reliable, Valid, Study Says

Analysis of hypoparathyroidism symptom diaries is an appropriate measure of disease symptoms and how they affect patients’ quality of life, a study shows.

The research article, “Psychometric evaluation of the hypoparathyroidism symptom diary,” was published in Dove Press.

Hypoparathyroidism symptom burden is substantial and can detract from health-related quality of life. However, it is difficult for clinicians to monitor these symptoms throughout patients’ daily lives.

Recently, a questionnaire called the Hypoparathyroidism Symptom Diary (HPT-SD) was established to assess the key symptoms and effects of hypoparathyroidism from the patient perspective. It was developed according to recommendations in the U.S. Food and Drug Administration (FDA) guidance for industry.

The questionnaire uses a 13-item tool to assess relevant symptoms, including:

• Physical: muscle cramping, tingling, muscle spasms/twitching, fatigue;
• Cognitive: cognition, anxiety, sadness, depression;
• Quality of life: effects on sleep, ability to exercise, ability to work, family relationships.

Researchers from RTI Health Solutions and Shire (now part of Takeda) evaluated the reliability and validity of the Hypoparathyroidism Symptom Diary in reporting psychometric data — information relating to mental and behavioral abilities.

“The goal is for the hypoparathyroidism symptom diary to be a brief, useful tool for assessing symptoms and impacts … from the patient perspective, and to use the hypoparathyroidism symptom diary in future studies that evaluate disease burden or treatment efficacy relating to symptom improvement,” researchers said.

Fifty-two adult participants completed the HPT-SD. They ranged in age from 24 to 78, with an average age of 51. To test the validity of HPT-SD, researchers had the participants complete three  outcome questionnaires:

1. The Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) Version 3: Higher scores indicate better cognitive functioning;
2. The Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue) Version 4: Higher scores indicate less fatigue;
3. The Hospital Anxiety and Depression Scale (HADS): Higher scores indicate worse anxiety or depression.

As expected, HPT-SD was oppositely linked with FACT-Cog and FACIT-Fatigue: increased hypoparathyroidism symptoms correlated with worse cognitive function and more fatigue. Similarly expected, HPT-SD scores were linked with HADS scores, indicating that increased hypoparathyroidism symptoms correlate with worse anxiety or depression.

To test the reliability of HPT-SD, the researchers wanted to see how each of the 13 HPT-SD item scores correlated with one another. They found that all 13 scores were linked, some more than others.

For example, items from categories for physical symptoms (i.e. muscle spasms or twitching strongly, muscle cramps, tingling, and numbness) were more linked with one another than with items from cognitive symptoms or quality of life.

Of all items, anxiety and depression were the most correlated. Also, strong correlations were observed between physical fatigue and impact on work as well as sadness or depression and impact on relationships. This suggests that there may be different symptom drivers for different HPT-related impacts.

“The present study provides important results regarding the psychometric properties of the HPT-SD in a sample of individuals with [hypoparathyroidism],” researchers said.

“The 13 HPT-SD items generally met accepted psychometric criteria and corroborate the findings of the qualitative research undertaken in the development of the HPT-SD. Collectively, the results of the psychometric analyses indicate that the HPT-SD is an appropriate measure of HPT-related symptoms and impacts.”