Researchers develop, validate eight GI symptom scales
Using the NIH Patient-Reported Outcomes Measurement Information System framework, researchers have developed and validated eight gastrointestinal symptom scales for use in clinical care and research across the full spectrum of GI disorders.
To create a standardized and comprehensive set of patient-reported outcomes in gastroenterology, Brennan Spiegel, MD, MSHS, department of gastroenterology and health services, Cedars-Sinai Medical Center, Los Angeles, Dinesh Khanna, MD, MSc, division of rheumatology, University of Michigan, and colleagues developed the NIH PROMIS GI symptom scales in three phases during 4 years.
In phase one they developed candidate items by performing a systematic literature review and conducting 12 disease-specific focus groups involving 102 GI patients. Phase two involved a qualitative item review. It resulted in 102 final items based on PROMIS standards and additional patient cognitive interviews (n=28) that investigators found to be simple, understandable and relevant to patients. In phase three the researchers performed quantitative psychometric analyses of the resulting symptom scales in a US general population control sample (n=1,177) and 865 patients with irritable bowel syndrome, inflammatory bowel disease, systemic sclerosis and other common GI disorders.
Researchers found that each scale had high internal reliability and construct validity compared with legacy instruments. Based on confirmatory factor analyses and item response theory modeling, scales were created for:
- gastroesophageal reflux (13 items)
- disrupted swallowing (seven items)
- diarrhea (five items)
- bowel incontinence/soilage (four items)
- nausea and vomiting (four items)
- constipation (nine items)
- belly pain (six items)
- gas/bloat/flatulence (12 items)
“In conclusion, we developed the NIH PROMIS GI symptom scales — a publicly available set of valid and reliable [patient-reported outcomes] for use in people with GI symptoms,” the researchers concluded. “The eight scales can be used together or individually for clinical practice and clinical research in a disease-agnostic manner. The scales are broadly applicable across populations, GI symptoms, GI diseases, and demographics.”
Disclosure: See the study for a full list of relevant financial disclosures.