Journal Articles

Published Research

The following is a summary of journal publications by Associate Professor Knowles. Click on the references below for further details.

Journal Articles


Mikocka-Walus, A., &Knowles. S.R. (2018). Editorial: anxiety and depression associated with mucosal healing in coeliac disease. Alimentary Pharmacology & Therapeutics.


The relationship between coeliac disease and psychological comorbidity is complex, with symptoms of anxiety and depression commonly identified in coeliac cohorts1 and associated with poorer gluten‐free diet (GFD) adherence.24 However, while maintaining a GFD is ideal for disease management, it is also recognised to be challenging both practically and emotionally.5 The study conducted by Ludvigsson et  al6 provides a valuable exploration of the relationship between psychological comorbidity and mucosal healing associated with maintaining a GFD.

In a nationwide longitudinal population‐based cohort study involving 7648 individuals, Ludvigsson et  al6 explored the association between diagnosis of anxiety or depression and its relationship to mucosal healing. The authors found that the risk of developing anxiety was 2.8 per 1000 person‐years of follow‐up in the mucosal healing group (n = 4331) vs 2.1 per 1000 in the group identified with persistent villous atrophy (n = 3317). Likewise, rates of depression were higher in the mucosal healing vs persistent villous atrophy group (3.8 vs 3.3 per 1000 person‐years of follow‐up). Both anxiety and depression were not common in the sample (3% and 4% respectively), and as the diagnostic codes and medications rather than screening scales or psychological/psychiatric interviews were used, the low prevalence may reflect a more severe symptomatology.

While there was some evidence for a higher psychotropic prescription rates in the persistent villous atrophy group vs mucosal healing group, these findings were not significant. The authors concluded that mucosal healing was associated with a greater risk of developing anxiety and depression, and that this may be due to the burden of the treatment or individuals living with anxiety/depression being more attentive to maintaining a GFD.

Indeed, for some patients, the everyday burden to maintain a GFD may lead to depression and ongoing anxiety about food choices, potential cross‐contamination, accidental, or deliberate GFD transgressions. The development of anxiety and/or depression may also promote adherence to a GFD. This may be due to a fear of coeliac symptoms or as a way to maintain or have some control in their life. Both purported mechanisms relating to the development of anxiety and depression in mucosal healing are not necessarily independent of each other and may well also be influenced by multiple factors unexplored in the research by Ludvigsson et  al, including anxiety and depression symptom severity, other psychological and physiological comorbidities, illness perceptions, self‐efficacy, and coping styles. Further longitudinal research which accounts for the identified limitations is likely to better elucidate the mechanisms underpinning anxiety and depression in coeliac cohorts and how it relates to mucosal healing.

Nevertheless, Ludvigsson et  al6 provide important evidence for the interplay between mucosal healing and psychological comorbidity, and the significant psychological costs associated with maintaining a GFD. Given this, along with utilising a GFD as directed by dieticians and gastroenterologists, it seems that the integration of mental health professionals to identify and address psychological comorbidities is not only warranted but also likely to lead to improved physical and psychological health.




Massuger, W., Moore, G.T.C., Andrews, J., Kilkenny, M., Reyneke, M., Knowles, S., Purcell, L., Alex, G., Buckton, S., Page, A.T., Stocks, N., Cameron, D., Manglaviti, F., Pavli, P. (2018). The Crohn’s & Colitis Australia Inflammatory Bowel Disease Audit: Measuring the quality of care in Australia. Internal Medicine Journal.



To audit the quality of care received by patients admitted for inflammatory bowel disease (IBD) across Australia against national IBD Standards.



Retrospective cross‐sectional survey and clinical audit assessing organisational resources, clinical processes and outcome measures.



Australian hospitals.



Hospitals that care for inpatients with Crohn’s disease or ulcerative colitis.


Main outcome measures

Adherence to national IBD Standards and comparison of quality of care between hospitals with and without multidisciplinary IBD services.



71 hospitals completed the organisational survey. Only one hospital had a complete multidisciplinary IBD service and 17 had a Partial IBD Service (IBD nurse, helpline and clinical lead). 1440 inpatient records were reviewed from 52 hospitals (mean age 37 years; 51% female, 53% Crohn’s disease), approximately 26% of IBD inpatient episodes over a 12‐month period in Australia. These patients were chronically unwell with high rates of anaemia (30%) and frequent readmissions (40% within two years). In general, care was inconsistent, and documentation poor. Hospitals with a Partial IBD Service performed better in many process and outcome measures: for example, 22% reduction in admissions via emergency departments and greater adherence to standards for safety monitoring of biologic (89% vs 59%) and immunosuppressive drugs (79% vs 55%) in those hospitals than those without.



Patients admitted to hospital suffering from IBD are young, chronically unwell, and are subject to substantial variations in clinical documentation and quality of care. Only one hospital met accepted Standards for multidisciplinary care; hospitals with even a minimal IBD service provided improved care.



Knowles, S.R., Graff, L.A., Wilding, H., Hewitt, C., Keefer, L., & Mikocko-Walus, A. (2018). Quality of life in inflammatory bowel disease: A systematic review and meta-analyses - Part I. Inflammatory Bowel Diseases, 24(4), 742-751. doi: 10.1093/ibd/izx100.


Background: Quality of life (QoL) is commonly assessed in IBD; the relationship of QoL within IBD states and relative to others has not been comprehensively evaluated. This systematic review, published across two papers, evaluates 5 key QoL comparisons. Part I, presented here, examines between-disease comparisons: (1) IBD/healthy(general) population (2) IBD/other medically ill groups; Part II examines within-disease comparisons: (3) active/inactive disease (4) UC/CD and (5) change over time. Outcomes using generic versus IBD-specific QoL measures were also examined.

Methods: Adult and paediatric studies were identified through systematic searches of 7 databases from the 1940s (where available) to October 2015. Results: Of 6,173 abstracts identified, 466 were selected for final review based on controlled design and validated measurement; 30 unique studies (23 adult, 7 paediatric) addressed the between-disease comparisons. The pooled mean QoL scores were: (1) lower in adult and paediatric IBD samples compared to healthy controls (n=19), and for both mental and physical QoL, where measured; and (2) higher but not significant for those with IBD compared to various medically ill controls (n=15). Findings were consistent across IBD-specific and generic QoL measures. Study quality was generally low to moderate. The most common measures of QoL were the disease-specific IBDQ and generic SF-36 (adults), and the generic PedsQL (children).

Conclusions: There was robust confirmation that QoL for individuals with IBD was poorer than for healthy individuals, for both adults and children. QoL in IBD may be better relative to some other GI and non-GI medical conditions for children.


Knowles, S.R., Keefer, L., Wilding, H., Hewitt, C., Graff, L.A., & Mikocko-Walus, A. (2018). Quality of life in inflammatory bowel disease: A systematic review and meta-analyses - Part II. Inflammatory Bowel Diseases, 24(5), 966-976. doi: 10.1093/ibd/izy015.


Background: There has been burgeoning interest in quality of life (QoL) in IBD in recent decades, with hundreds of studies each year now assessing this outcome. This paper is Part II of a systematic review evaluating 5 key QoL comparisons within IBD states and relative to others without IBD. Part I examined QoL comparing IBD and healthy/general population, and other medically ill groups. Part II, presented here, examines within-disease comparisons of active/inactive disease, UC/CD, and change over time. Outcomes using generic versus IBD-specific QoL measures were also examined.

Methods: Adult and paediatric studies were identified through systematic searches of 7 databases from the 1940s (where available) to October 2015.  Results:  Of 6,173 abstracts identified, 466 were selected for final review based on controlled design and validated measurement, of which 83 unique studies (75 adult, 8 paediatric) addressed the within-disease comparisons. The pooled mean QoL scores were significantly lower in active versus inactive IBD (n=26) and for those with CD versus UC (n=37), consistently across IBD-specific and generic QoL measures, for almost all comparisons. There was significant improvement in QoL over time (n=37). Study quality was generally low to moderate. The most common measures of QoL were the disease-specific IBDQ and generic SF-36 (adults), and the IBD-specific IMPACT (children).

Conclusions: For adults in particular, there was strong confirmation that QoL is poorer during active disease, and may be poorer for those with CD. The finding that QoL can improve over time may be encouraging for individuals with this chronic disease.


Kuoch, K.L.J., Meyer, D., Austin, D.W., & Knowles, S.R. (in press 24/11/2018). Development and Validation of the Bladder and Bowel Incontinence Phobia Severity Scale (BBIPSS). Journal of Cognitive Psychotherapy.


The current research investigates the development and validation of the Bladder and Bowel Incontinence Phobia Severity Scale (BBIPSS). Over two studies, two independent samples consisting of university students and respondents from the general public were used to validate the scale (study 1 n = 226; study 2 n = 377). A 15-item, two-factor model was confirmed in study 2 where strong construct (convergent and divergent) validity was demonstrated. The BBIPSS did not display significant correlations with openness and gender (divergent validity) and displayed significant correlations with depression, anxiety and stress scores (DASS), alongside paruresis and parcopresis scores (SBBS; convergent validity) and the BoBCAtS. The BBIPSS also demonstrated strong test-retest reliability (bladder r = 0.89; bowel r = 0.86) in a small sample of adults (n = 13). Overall, this scale provides researchers and clinicians with a reliable and psychometrically valid assessment tool to measure bladder and bowel incontinence phobia severity.



Mikocka-Walus, A., & Knowles. S.R. (2018). Editorial: Anxiety and depression in inflammatory bowel disease. Alimentary Pharmacology & Therapeutics, 48(6), 686-687.



Cook, S., Meyer, D., Knowles, S.R. (2018). Relationships between psychoevolutionary fear of evaluation, cognitive distortions, and social anxiety symptoms: A preliminary structural equation model. Australian Journal of Psychology.

Social anxiety disorder is a mental health condition that affects 4.7% of Australians each year. The complex interplay between psychoevolutionary and cognitive models has become the focus of research in recent years, particularly with the development of the bivalent fear of evaluation model (i.e., negative and positive evaluation fears). The present study aimed to test a model of social anxiety symptoms using structural equation modelling, integrating previously fragmented evidence. A sample of 255 participants (75.3% female; Mage = 31.9, SD = 10.3) undertook an online survey, including Social Phobia Scale, Brief Fear of Negative Evaluation—Straightforward, Fear of Positive Evaluation, Concerns of Social Reprisal, and Disqualifications of Positive Social Outcomes measures. The hypothesised model for social anxiety symptoms described the data reasonably well (χ2(1) = 4.917, p = .027, CFI = .995, GFI = .992, SRMR = .017), explaining 57.1% of social anxiety variance. Study hypotheses were supported with bivalent fear of evaluation accounting for unique variance in cognitive distortions, which in turn accounted for unique variation in social anxiety symptoms. Effect sizes indicate bivalent fears of evaluation and disqualification of positive social outcomes as important predictors of social anxiety symptoms. Although replication in a clinical cohort and experimental confirmation are needed, the findings suggest a focus on disqualification of positive social outcomes to alleviate social anxiety symptoms.



Moller, S., Apputhurai, P., Knowles. S.R. (in press 09/05/2018). Confirmatory factor analyses of the ORTO 15-, 11- and 9-item scales and recommendations for suggested cut-off scores. Eating and Weight Disorders (EAWD). doi: 10.1007/s40519-018-0515-0.


Aims: To explore the validity and recommend cut-off scores in an English-speaking sample for 9, 11, and 15-item versions of the ORTO measure for orthorexia, a proposed eating disorder characterised by a pathological obsession with consuming only ‘healthy’ foods.

Materials and methods: The sample comprised of 585 participants (82.4% female) who completed an online questionnaire containing the ORTO-15, Eating Attitudes test, Obsessive Compulsive Inventory Revised. A series of Confirmatory Factor Analyses were conducted to test model fit. Binary logistic linear regression and receiver-operating-characteristics (ROC) analyses were used to obtain cut-offs.

Results and conclusion: Results showed that none of the three published versions (9, 11, and 15-item) of the ORTO produced an acceptable model. Subsequent exploratory and confirmatory factor analyses yielded a seven-item version of the ORTO (ORTO-7) with a strong and stable factor structure. Analysis of cut-offs revealed that a cut-off score of equal or greater than 19 on the ORTO-7 represents probable orthorexia.

Level of evidence: Level V, descriptive study.



Cassar, G. E., Knowles, S., Youssef, G. J. Moulding, R., Uiterwijk, D. Waters, L. & Austin, D.W. (2018). Examining the mediational role of psychological flexibility, pain catastrophizing, and visceral sensitivity in the relationship between psychological distress, irritable bowel symptom frequency, and quality of life. Psychology, Health & Medicine, 8,1-14. doi: 10.1080/13548506.2018.1476722.

The aim of the current study was to use Structural Equation Modelling (SEM) to examine whether psychological flexibility (i.e. mindfulness, acceptance, valued-living) mediates the relationship between distress, irritable bowel syndrome (IBS) symptom frequency, and quality of life (QoL). Ninety-two individuals participated in the study (12 male, 80 female, Mage = 36.24) by completing an online survey including measures of visceral sensitivity, distress, IBS-related QoL, mindfulness, bowel symptoms, pain catastrophizing, acceptance, and valued-living. A final model with excellent fit was identified. Psychological distress significantly and directly predicted pain catastrophizing, valued-living, and IBS symptom frequency. Pain catastrophizing directly predicted visceral sensitivity and acceptance, while visceral sensitivity significantly and directly predicted IBS symptom frequency and QoL. Symptom frequency also had a direct and significant relationship with QoL. The current findings suggest that interventions designed to address unhelpful cognitive processes related to visceral sensitivity, pain catastrophizing, and psychological distress may be of most benefit to IBS-related QoL.



Halmos, E.P., Deng, M., Knowles, S.R., Sainsbury, K., Mullan, B., Tye-Din, JA. (2018). Food knowledge and psychological state predicts adherence to a gluten-free diet in a survey of 7000 Australians and New Zealanders with coeliac disease. Alimentary Pharmacology & Therapeutics, 48(1):78-86. doi: 10.1111/apt.14791.


BACKGROUND: A gluten-free diet treats coeliac disease, but its efficacy depends on strict adherence. A variety of patient factors may influence adherence but have not been well described at a population level.

AIM: To comprehensively assess the patient factors that influence gluten-free diet adherence in patients with coeliac disease.

METHODS: Patients with coeliac disease completed an online survey comprising the validated Celiac Dietary Adherence Test in addition to data on demographics, details of diagnosis and management and assessment of diet knowledge, quality of life and psychological distress. Survey data were analysed for predictors of adherence and quality of life.

RESULTS: Of 7393 responses, 5310 completed the Celiac Dietary Adherence Test and 3230 (61%) were adherent to a gluten-free diet. Multivariate regression showed older age, being male, symptoms after gluten ingestion, better food knowledge and lower risk of psychological distress were independent predictors of adherence (each P ≤ 0.008). Additionally, dietary adherence was associated with better quality of life (P < 0.001; multiple regression). Respondents who considered themselves to have poor food knowledge were more likely to incorrectly identify gluten-free foods, but could still recognise gluten-containing foods, suggesting that poor knowledge may lead to over-restriction of diet.

CONCLUSIONS: Poor knowledge of a gluten-free diet and psychological wellbeing were independent modifiable risk factors for inadequate adherence to a gluten-free diet in patients with coeliac disease. Involvement of both a dietitian and mental health care professional, in the presence of psychological distress, is likely to be necessary to improve adherence and health outcomes.



Jackson, B., Con, D., Gorelik, A., Liew, D., Knowles, S.R., Cruz, P. (2018). Examination of the relationship between disease activity and patient reported outcome measures in an Inflammatory Bowel Disease cohort. Internal Medicine Journal, 48(10), 1234-1241. doi: 10.1111/imj.13937


BACKGROUND: The extent to which disease activity impacts patient-reported outcomes (PRO) is unclear.

AIMS: To examine the relationship between disease activity and PRO.

METHODS: Adult inflammatory bowel disease (IBD) patients attending a tertiary clinic from May to June 2015 were included. Assessment of disease activity (Simple Clinical Colitis Activity Index (SCCAI), Harvey Bradshaw Index (HBI)), IBD knowledge (CCKNOW), medication adherence (MMAS8), psychological distress (Hospital Anxiety and Depression Scale (HADS)), work productivity (WPAI) and quality of life (IBDQ) was performed to investigate any correlations between disease activity and PRO.

RESULTS: A total of 81 participants was included: 49% female, 57% Crohn disease (CD), 38% ulcerative colitis (UC) and 5% IBD-unclassified, with a median age of 34 years. At least mild levels of depression were present in 21 of 81 (26%) of patients; 37 of 81 (46%) expressed some level of anxiety. A moderate-to-strong correlation was found between disease activity and depression in UC (r = 0.84, P = 0.002) but not in CD (r = 0.53, P = 0.29). Disease activity correlated with: overall work impairment due to health (r = 0.85, P = 0.001), health-related impairment while working (r = 0.76, P = 0.02) and percentage of activity impaired due to health (r = 0.83, P = 0.002) in UC only.

CONCLUSIONS: Disease activity significantly affects mood and work productivity in patients with UC. Monitoring patients’ ability to function and work, rather than minimising disease activity alone, should become a routine part of IBD care.



Knowles, S.R., & Apputhurai, P. (2018). Development and Validation of the Mental Health Seeking Apprehension Scale (MHSAS). Journal of Psychology and Psychotherapy Research, 5, 1-9.


As many as 1 in 5 individuals currently experience mental health issues, and that only a minority seek help from mental health professionals. This paper outlines the development and validation of the Mental Health Seeking Apprehension Scale (MHSAS). MHSAS was validated across three studies using both university and community samples. In the first study, exploratory factor analysis revealed a nine-item two-factor scale (N=231), which was confirmed in the second study (N=208). The first factor related to mental health stigma (e.g., embarrassed about help-seeking, not wanting others to know) while the second was related to ambivalence toward seeking help (e.g., nothing changes problems, professional may not be helpful). Based on a combination of Study 1 and 2 datasets, the third study (N=439) analysed MHSAS and help-seeking behaviour. Results suggest that greater perceived stigma and ambivalence were associated with not seeking mental health support and also greater psychological distress. The research provides good preliminary evidence that the MHSAS is a brief psychometrically valid measure of mental health help seeking apprehension. MHSAS can be utilised by health professionals and researchers to screen for apprehension relating to seeking mental health support and identify potential barriers preventing utilisation of mental health services when needed. 



Sainsbury, K., Halmos, E.P., Knowles, S.R., Mullan, B., Tye-Din, JA. (2018). Maintenance of a gluten free diet in coeliac disease: The roles of self-regulation, habit, psychological resources, motivation, support, and goal priority. Appetite, 125, 356-366. doi: 10.1016/j.appet.2018.02.023.


INTRODUCTION: A strict lifelong gluten free diet (GFD) is the only treatment for coeliac disease (CD). Theory-based research has focused predominantly on initiation, rational, and motivational processes in predicting adherence. The aim of this study was to evaluate an expanded collection of theoretical constructs specifically relevant to the maintenance of behaviour change, in the understanding and prediction of GFD adherence.

METHODS: Respondents with CD (N = 5573) completed measures of GFD adherence, psychological distress, intentions, self-efficacy, and the maintenance-relevant constructs of self-regulation, habit, temptation and intentional and unintentional lapses (cognitive and behavioural consequences of lowered or fluctuating psychological resources and self-control), motivation, social and environmental support, and goal priority, conflict, and facilitation. Correlations and multiple regression were used to determine their influence on adherence, over and above intention and self-efficacy, and how relationships changed in the presence of distress.

RESULTS: Better adherence was associated with greater self-regulation, habit, self-efficacy, priority, facilitation, and support; and lower psychological distress, conflict, and fewer self-control lapses (e.g., when busy/stressed). Autonomous and wellbeing-based, but not controlled motivations, were related to adherence. In the presence of distress, the influence of self-regulation and intentional lapses on adherence were increased, while temptation and unintentional lapses were decreased.

DISCUSSION: The findings point to the importance of considering intentional, volitional, automatic, and emotional processes in the understanding and prediction of GFD adherence. Behaviour change interventions and psychological support are now needed so that theoretical knowledge can be translated into evidence-based care, including a role for psychologists within the multi-disciplinary treatment team.



Woodhouse, S., Hebbard, G., & Knowles, S.R. (2018). Exploring symptom severity, illness perceptions, coping styles and wellbeing in gastroparesis patients using the Common Sense Model. Digestive Diseases and Sciences, 63(4),958-965.


AIMS: This study aimed to examine the relationships between gastroparesis symptom severity, illness perceptions, coping styles, quality of life (QoL), and psychological distress in patients with gastroparesis, guided by the common sense model.

METHODS: One hundred and seventy-nine adults with gastroparesis (165 females, 14 males; mean age 41.82 years) completed an online questionnaire. The Gastroparesis Cardinal Symptom Index was used to measure gastroparesis symptom severity, QoL was explored using the PAGI-QOL, illness perceptions were measured using the Brief Illness Perception Questionnaire, the Carver Brief COPE scale assessed coping styles, and psychological distress was investigated using the DASS21.

RESULTS: Structural equation modeling resulted in a final model with excellent fit. Gastroparesis symptom severity directly influenced illness perceptions (β = .52, p < .001) and QoL (β = .30, p < .001). Illness perceptions directly influenced maladaptive coping (β = – .64, p < .001), psychological distress (β = – .32, p < .001), and QoL (β = .30, p = .01). Maladaptive coping directly influenced psychological distress (β = .62, p < .001), which in turn had a direct influence on QoL (β = – .38, p < .001).

CONCLUSIONS: The final model showed that the influence of gastroparesis symptom severity on psychological distress was fully mediated by illness perceptions, while the influence on QoL was partially mediated by illness perceptions. The study provides guidance for the development of psychological interventions targeted toward improving mediating psychological factors.



Knowles, S.R., Andrews, J., & Porter, A. Crohn’s & Colitis Australia, IBD Support Australia and the Australian Inflammatory Bowel Disease Association (2018). Predictors of impaired mental health and support seeking in adults with inflammatory bowel disease: An online survey. Gastroenterology Nursing, 41(1), 38-42. DOI: 10.1097/SGA.0000000000000251.


This study explored the possible factors associated with psychological distress in adults with inflammatory bowel disease (IBD) and also engagement in mental health services (MHS) in those reporting distress in a large Australian cohort. Participants with IBD completed an online survey assessing perceived IBD activity (Manitoba Index; MI), mental health status (K10), demographic details, and engagement with MHS for IBD-associated issues. Of 336 participants, 76.5% perceived themselves as having active disease over the past 6 months, and on K10 scores, 51.8% had a mental health issue. Of participants with a mental health issue, only 21.3% were currently receiving mental health support. A stepwise logistic regression analysis correctly classified 78.7% of the status of receiving mental health support, with lower income (<$60,000 per annum) the only significant predictor. Paradoxically, the degree of psychological distress did not correlate with seeking mental health support. The data show that in individuals with ongoing symptoms attributed to active IBD, mental health issues are highly prevalent, with older age and higher income being additional drivers of mental health issues. The greater challenge, however, seems not to be identifying mental health issues, but in getting those in need to engage in MHS.