Development, validation, and applicability of a symptoms questionnaire for lactose malabsorption screening

Area of Science:

• Gastroenterology
• Digestive Health
• Clinical Diagnostics

Background:

• Lactase deficiency is globally prevalent.
• A reliable symptom scale is needed to identify lactose malabsorption.
• Current diagnostic methods can be improved for wider application.

Purpose of the Study:

• To develop and validate a symptom questionnaire for lactose malabsorption.
• To assess the questionnaire's ability to identify individuals diagnosed via hydrogen breath testing.
• To establish a tool for excluding patients from studies based on symptom scores.

Main Methods:

• A five-item visual analogue scale questionnaire was administered to 292 patients post-lactose breath test.
• A subset of 171 patients completed the questionnaire twice: at home and after a breath test.
• Patients were classified as absorbers or malabsorbers based on hydrogen breath test results.

Main Results:

• Malabsorbers reported significantly higher scores for diarrhea, cramping, and flatulence.
• The total questionnaire score was significantly higher in malabsorbers (17.5 vs. 3.0, P<0.01).
• A cut-off score of 6.5 demonstrated optimal discrimination (sensitivity 0.75, specificity 0.67).

Conclusions:

• A five-item symptom questionnaire for lactose malabsorption has been developed and validated.
• The questionnaire is a valid tool for identifying lactose malabsorption.
• A total score below 7 can be used to exclude patients from future studies.