Short summary

This study aims to develop a Danish version of an internationally disease-specific quality of life (QoL) questionnaire for patients suffering from anorexia nervosa (AN). Furthermore, QoL is assessed in patients who have gone through shorter or longer treatment. 

Rationale

Eating disorders (ED) comprise a multitude of symptoms involving a disturbed body image and a preoccupation with food/weight. EDs are often difficult to treat, in part due to the lack of motivation for improvement. AN have the highest mortality rate of any psychiatric disease and less than half of patients will recover from the disease. Studies have found that patients suffering from AN have impaired QoL compared to the general population. It has also been suggested that despite improvement in clinical parameters, patients report deterioration in QoL, which is in line with a study finding low agreement between patient perceived outcome and clinician assessed characteristics. To evaluate the patients' perception of their disease, it is important to develop reliable and valid assessment tools. Previously generic questionnaires have been used to assess QoL in Danish ED patients, as no disease-specific questionnaires have been developed. Translating and validating a disease-specific questionnaire would provide a useful tool in assessing current treatment and in developing new treatment options.

Description of the cohort

Preparatory study: Testing and adaptation of the Danish version of the eating disorder quality of life scale (EDQLS) for use by 13-17 year olds with AN.

Study 1: Concurrent validity and internal consistency. EDQLS, ED symptomatology, distress, social function and generic QOL assessed in different clinical samples of AN patients aged 13-17 and +18 years and in a sample of age-matched healthy controls within a normal weight range.

Study 2: Test-retest reliability. EDQLS completed twice with a 2-4 week interval in a sample of weight- and treatment-stable outpatients and controls aged 13-17 and +18 years.

Study 3: Sensitivity to change. EDQLS applied three times over a 4-6 week interval in a sample of AN inpatients aged 13-17 and +18 years.

Study 4: Patients outside the established treatment. EDQLS, ED symptomatology, distress, social function and generic QoL score among members and followers with BMI under 18 recruited from the official website for the national patient organisations.

Patients will be recruited through the Centre for Eating Disorders, Odense University Hospital.

Potential control subjects will be identified through public call for proposals. The proposals will be posted at institutions of further education and public schools in Odense with students in the appropriate age range.

Data and biological material

Screening questionnaire: Patients will be asked to fill out a questionnaire regarding current weight, height and information regarding current medication. 

Disease-specific quality of life: The Eating Disorder Quality of Life Scale (EDQLS) is a disease-specific quality of life questionnaire developed for use in eating disorders. It consists of 40 items across 12 domains. In each domain patients respond on a 5-point likert scale (strongly agrees through strongly disagree). Each domain has three questions, except the eating domain which consists of six questions. The domains are: school/work, family and close relationships, relationships with others, future, feelings, appearance, leisure, values and beliefs, cognitive, physical health, psychological health and eating. Each score is summed using a scoring algorithm with a higher total score indicating higher quality of life (0-200).

The WHO-5 Well-being Index (WHO-5): The WHO-5 Well-Being Index is focused on the positive sides of wellbeing. It consists of 5 items. The raw scores are transformed to a score from 0 (worst thinkable well-being) to a 100 (best thinkable wellbeing). A score under 50 suggest poor emotional well-being. In adults, the WHO-5 has proved to be a highly sensitive screener for depression.

Generic quality of life: The Short Form-36 (SF-36) is a generic, self-report questionnaire measuring health-related quality of life (HRQOL) and consists of eight subscales that assess physical functioning (PF), Patient-reported outcome, role limitations due to physical health problems (RP), bodily pain (BP), general health perception (GH), vitality (VT), social functioning (SF), role limitations due to emotional problems (RE) and general mental health (MH). The sum for each subscale is transformed into a 0-100 scale with higher scores indicating better HRQOL. The scores can be summarized in a mental component scale (MCS) and physical component scale (PCS), where a score of 50 represents the general population.

Eating disorder symptomatology: Patients' eating disorder symptoms will be measured using the self-reported Eating Disorder Inventory-3, Danish version, EDI-3 15. It consists of 91 items and has 11 subscales: Drive for Thinness, Bulimia, Body Dissatisfaction, Ineffectiveness, Perfectionism, Interpersonal Distrust, Introspective Awareness, Maturity Fears, Asceticism, Impulse Regulation and Social Insecurity. Answers are given on a 6-point Likert scale. The higher the score, the greater the manifestation of the trait in question. It is validated in Danish.

Depression: The Beck Depression Inventory II (BDI-II) is a 21-question multiple-choice self-report inventory, one of the most widely used psychometric tests for measuring the severity of depression. In its current version, the BDI-II is designed for individuals aged 13 and over, and is composed of items relating to symptoms of depression such as hopelessness and irritability, cognitions such as guilt or feelings of being punished, as well as physical symptoms such as fatigue, weight loss, and lack of interest in sex.

Impairment in functioning: Work and Social Adjustment Scale (WSAS) is an 8-item self-rating questionnaire (Likert scale) validated for use across the full spectrum of psychiatric disorders and it represent functional and societal dimensions of illness.

Collaborating researchers and departments

Department of Endocrinology, Center for Eating Disorders, Odense University Hospital

• Professor René Klinkby Støving, MD, PhD

Department of Psychiatry for Children and Adolescent, Center for Eating Disorders, Odense University Hospital

• Postdoc Laura Al-Dakhiel Winkler, MD, PhD

Department of Clinical Medicine, Psykiatrien Region Zealand

• Clinical Associate Professor Sidse Marie Hemmingsen Arnfred, MD, M.Sc, PhD, DMSc.

• Chief Consultant Michael Einar Røder, MD, DMSc

Department of Clinical Research, University of Southern Denmark

• Assistant Professor Claire M. Gudex, MBChB, MPH, MD.

Centre for Telepsychiatry in the Region of Southern, University of Southern Denmark

• Assistant Professor Mia Beck Lichtenstein, PhD

Department of Community Health Sciences and Psychiatry, Faculty of Medicine, University of Calgary, Health Sciences Centre, Calgary, Canada

• Carol E. Adair