Intentional and inadvertent non-adherence in adult coeliac disease. A cross-sectional survey

Highlights

• Non-adherence to the gluten-free diet involves intentional and inadvertent lapses.

• Intentional lapses are common but less frequent than inadvertent lapses.

• Contributing factors affect both types of non-adherence in different ways.

• Intention, perceived tolerance and self-efficacy predicted intentional lapses.

• Psychosocial factors do not explain inadvertent lapses as well as intentional ones.

Abstract

Adherence to a gluten-free diet is the mainstay of treatment for coeliac disease. Non-adherence is common as the diet is restrictive and can be difficult to follow. This study aimed to determine the rates of intentional and inadvertent non-adherence in adult coeliac disease and to examine the factors associated with both. A self-completion questionnaire was mailed to adult coeliac patients identified from the computer records of 31 family practices within the North East of England. We received 287 responses after one reminder. Intentional gluten consumption was reported by 115 (40%) of respondents. 155 (54%) had made at least one known mistaken lapse over the same period and 82 (29%) reported neither intentional nor mistaken gluten consumption. Using logistic regression analysis, low self-efficacy, perceptions of tolerance to gluten and intention were found to be independently predictive of intentional gluten consumption. A statistical model predicted 71.8% of cases reporting intentional lapses. Intentional non-adherence to the GFD was found to be common but not as frequent as inadvertent lapses. Distinguishing the factors influencing both intentional and inadvertent non-adherence is useful in understanding dietary self-management in coeliac disease.

Introduction

Coeliac disease (CD) is a chronic inflammatory intestinal disorder characterised by a heightened immunological response to ingested gluten in genetically susceptible individuals. Originally a disease of childhood, CD is now more frequently first diagnosed in adults and has a prevalence of around 1% in Europe and the US (Bingley et al., 2004, Dube et al., 2005, Lohi et al., 2007, West et al., 2003). This change in presentation is partly explained by the increasing use of serological tests for active case-finding and for targeted screening in high risk groups (Collin, 2005, Hin et al., 1999, Jones, 2007, Korponay-Szabo et al., 2005). Advances in diagnostic testing, together with improved recognition of CD (National Institute for Health, 2009), have also resulted in an increased number of individuals diagnosed with atypical, minimal or no symptoms (Mulder & Cellier, 2005). The mainstay of treatment for CD is strict life-long adherence to a gluten-free diet (GFD). For most patients, this results in full clinical and histological remission (Holmes & Catassi, 2000) and is associated with improvements in symptoms and quality of life (Midhagen & Hallert, 2003), a decrease in long term health risks and health gains for problems associated with CD such as infertility, fatigue (Siniscalchi et al., 2005), and depression (Hallert and Sedvall, 1983, Hallert et al., 2002, Whitaker et al., 2009). The GFD is restrictive and can be difficult for some patients to follow, however, and the most common cause of persistent symptoms is gluten consumption (Dewar et al., 2012, Hopper et al., 2007). This is compounded by confusing food labelling and the expense and limited availability of GF foods despite their availability on prescription in the UK and other European countries and increasing availability of GF foods in supermarkets. Adherence to the GFD is reported to range between 36% and 96% and is associated with a variety of demographic, psychosocial and clinical factors (Ford et al., 2012, Hall et al., 2009, Sainsbury and Mullan, 2011). Adherence is not usually conceptualised in behavioural terms, despite the acknowledgement of both intentional and inadvertent gluten consumption within the literature (Black and Orfila, 2011, Casellas et al., 2009, Dewar et al., 2012, Vahedi et al., 2003). No study has specifically examined the factors associated with each type of non-adherence in coeliac disease. Although the primary concern in terms of clinical outcomes is actual gluten consumption, greater understanding of these very different behaviours is important in understanding dietary self-management and may inform potential interventions. This study investigates the factors associated with both intentional and inadvertent gluten consumption in adults with CD.