GF Science: Health-Related Quality of Life
The GF Science series analyzes recent research on gluten-free related topics. I will provide a link to the original research (if possible), present a brief summary of the research, review the author-reported results, posit contextual factors that may affect these results, suggest practical ways to use this research in your life, and begin a discussion with you about some aspect of this research. Your participation is this discussion is essential to further the dialogue about this particular research as well as the overall importance of increased scientific research on gluten-free related topics.
DISCLAIMER: GF Science posts are intended to provide guidance about reading scientific articles to gather practical information for daily living. The information in this post should not be considered a substitute for professional medical advice.
Benefit on health-related quality of life of adherence to gluten-free diet in adult patients with celiac disease
Revista Española de Enfermedades Digestivas (peer-reviewed journal)
Vol. 107, No. 4, pp. 196-201, 2015
Authors: Francisco Casellas, Luis Rodrigo, Alfredo J. Lucendo, Fernando Fernández-Bañares, Javier Molina-Infante, Santiago Vivas, Mercé Rosinach, Carmen Dueñas and Josefa López-Vivancos
Researchers used surveys (see below) of self-reported behaviors and effects to evaluate 366 adult patients being treated at 7 different Spanish hospitals. All study participants were diagnosed (via positive blood test and endoscopic biopsy of duodenum) with Celiac Disease (CD) and followed a gluten-free diet (GFD) for at least one year prior to the study (median = 4 years). Researchers intended to study how adherence to the GFD affects CD patients’ health-related quality of life (HRQOL).
- Morisky Scale (5 questions with yes or no answer):
- “I sometimes forget to follow the diet”
- “I sometimes am not very careful in following the diet”
- “When I feel better, I sometimes stop the diet”
- “If I do not feel well, I sometimes stop the diet”
- “I never forget to follow the diet”
- Specific Celiac Disease-Quality of Life (CD-QOL) Questionnaire (“20 items…distributed into 4 dimensions: Dysphoria, limitations, health concerns, and inadequate treatment –that should be answered on a Likert scale”):
- “[It] yields an overall score expressed on a scale of 0 (worst quality of life) to 100 (best quality of life), and four domains, each expressed on the same 0-100 scale, where 100 corresponds to the best quality of life.”
- General EuroQOL-5D Questionnaire:
- “The first part assesses health state through five dimensions: Mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each of these dimensions includes three items related to three severity levels. As the result, 243 different health states may be obtained.”
- “In the second part, patients score their health state on a visual analogue scale ranging from 0 (worst imaginable health state) to 100 (best imaginable health state).”
“In CD, good adherence to a GFD and adequate symptom control result in improved HRQOL. Many patients consider that the lack of therapeutic alternatives to diet worsens their quality of life…This result can be interpreted in the sense that celiac patients on treatment perceive that not having other alternatives to the gluten-free diet for controlling the disease limits their quality of life.”
*The authors noted that study results were consistent with previous research on this subject.
Whenever you are analyzing scientific research, it is important to understand both the assumptions that make up the hypothesis as well as the study limitations. Comprehensive scientific research articles will include this information because it provides appropriate context for interpreting the results.
- “Celiac disease (CD), due to its chronic nature, impact on health, psychological distress, social and family connotations, and need for permanent treatment, adversely affects quality of life (HRQOL) of patients.”
- “…Following a GFD also generates difficulties and limitations in the life of patients with CD under treatment.”
- “Adequate treatment adherence, in this case to a GFD, is a determining factor in improving the health of celiac patients and for improving their HRQOL…”
- “…Asymptomatic patients diagnosed by serology, in contrast to what occurs with symptomatic cases, may even experience deterioration in their health perception during following of a GFD…”
- “It was not an objective of the study to determine the reasons for failure of treatment adherence or potential factors involved in this, and therefore psychological profiles of patients were not established that might have influenced this…”
- “…The lack of a measurement of quality of life before starting treatment.”
- This study was conducted only in Spain, but it was based on international research. It is important to note that cultural factors may skew results or affect assumptions used to create the hypothesis.
- These conclusions were based on self-reported survey results. Whenever using these types of tests, one must take into account unintentional biases of the survey-takers. Also, due to the self-administered aspect of the surveys, there was no objective standard for “perfect adherence” to the GFD—all results are based on the survey-takers subjective definition of adherence to the GFD.
- The authors noted that one of the surveys was used because it was the only one available (and not necessarily the best gauge of HRQOL): “…Adherence to the GFD was related to quality of life assessed with the specific questionnaire CD-QOL, because it is the only currently specific questionnaire translated and validated to Spanish available…”
- People not included in the study: (1) “Patients with celiac disease who could not read or understand questionnaires, with other relevant concomitant chronic diseases, or who refused to sign informed consent were excluded from the study.” (2) “…Fifteen patients did not answer Morisky test or did so incorrectly, and were not included in the statistical analysis of the study.” (3) People following a GFD who are not formally diagnosed with CD.
- While there was definitely a statistically significant correlation between adherence to a GFD and HRQOL, there is no definitive indicator of causation. In other words, it is possible that having a good HRQOL actually may help a patient better adhere to a GFD.
If you suffer great physical/mental/emotional symptoms from CD or other gluten intolerance, the initial difficulties/anxieties/frustrations of following a GFD will most likely feel worthwhile. However, if you don’t experience much suffering, you will be less likely to strictly adhere to GFD because the treatment affects HRQOL more than the actual disease.
I know that my life experience is very consistent with the results of this research study. Because I experienced significant physical/mental/emotional symptoms, my quality of life almost instantly improved once my symptoms started to disappear, despite the (very real) drawbacks to gluten-free living.