Aim
To identify the beliefs patients with BEB and HFS hold about their condition and treatment and to identify the relationships between these beliefs and clinical and psychosocial outcomes.
Study design
This cross-sectional study used baseline data from a single-masked randomised controlled trial (RCT) assessing the effectiveness of a patient-initiated BTX service compared to standard care [17].
Setting
This study was conducted in the nurse-led BTX clinic at Moorfields Eye Hospital (MEH) NHS Foundation Trust, London.
Participants
Participants were recruited from the nurse-led BTX clinic at MEH London. The hospital records of patients booked for the BTX clinic were screened by a research nurse for eligibility. Eligibility criteria included adults (>18 years of age) with a diagnosis of BEB or HFS, two stable doses of BTX previously, capacity to give informed consent, and able to communicate fluently in written and/or spoken English. Although BEB and HFS are different conditions they share many characteristics, including procedural aspects of the treatment and the cyclical nature of the response, hence including both in this research.
Ethical approval
Ethical approval for this study was obtained from the National Research Ethics Service, London – Queen Square (REC reference 15/LO/0439) in April 2015.
Procedure
Participants meeting the inclusion criteria were invited by letter to participate in the RCT two weeks before their clinic appointment, with an information sheet attached. Patients were approached by a member of the clinical team at their appointment to confirm if they wished to take part. Consenting participants received a questionnaire booklet with a freepost return envelope and completed the questionnaire at their clinic visit or at home.
Materials
The questionnaire pack asked for demographic information: age, gender, marital status, housing situation, ethnicity, employment status, and education level. Clinical measures were recorded by the treating clinician including diagnosis, duration of BTX treatment, number of previous cycles, and frequency of previous cycles.
Severity and frequency of spasms
BEB or HFS severity was measured using the Jankovic Rating Scale (JRS) [18], consisting of two subscales measuring severity and frequency of spasms and found to be valid and reliable in BEB [19]. For patients with HFS an additional rating scale measuring the severity and frequency of cheek involvement developed previously for HFS research [20] was used. Higher scores indicate severe and more frequent spasms, with a maximum total score of 8 for each rating scale
Illness disability
The Blepharospasm Disability Index (BSDI)© [21] was used to measure disability when performing six daily activities: reading, driving, watching TV, shopping, walking and doing everyday activities. Responses ranged from “no impairment” to “no longer possible due to illness”, with a “not applicable” option available for each item and higher scores indicating greater disability. This valid and reliable measure [19] is also recommended for use with patients with HFS [20].
Illness beliefs
Illness perceptions were measured using the Revised Illness Perceptions Questionnaire (IPQ-R), which is divided into 3 sections. The identity subscale is presented as a list of 14 common symptoms [7], e.g. fatigue. Following recommendations by the original authors, four symptoms related to BEB and HFS were added: (i) frequent blinking, (ii) irritation of the eye, (iii) uncontrollable eye closure and, (iv) muscle twitching. Respondents indicate whether they have experienced each symptom and whether symptoms are related to their condition. The maximum score was 18, with higher scores demonstrating a belief that more symptoms are associated with the condition.
The original IPQ-R contained 38 items in the second section. The factor structure, validated in a sample of patients with eight illnesses, included timeline acute/ chronic, timeline cyclical, consequences, personal control, treatment control, illness coherence and emotional representations [7]. Patients with BEB and HFS were not included in the original validation, so to capture the specific beliefs of these patients, construct validity was assessed by the authors using a principal component analysis. The 38 IPQ-R items were found to be structured by 10 components in this sample of patients with BEB and HFS: timeline acute, timeline chronic, timeline cyclical, consequences, positive personal control, negative personal control, illness uncertainty, treatment control, illness coherence and emotional representations. Higher scores represent strongly held beliefs about chronicity, the cyclical nature of BEB or HFS, their negative consequences, and negative emotional responses towards the conditions. Higher scores on positive personal control, treatment control or coherence dimensions represent positive beliefs about controllability of BEB of HFS and their treatment and a personal understanding of their illness. Higher scores on the negative personal control and uncertainty domains indicate beliefs in being unable to control the conditions and that they cause uncertainty.
The third section measuring causes includes 18 items. A factor analysis revealed four types of causal beliefs held by the eight illness groups assessed for the original questionnaire development: psychological attributions, risk factors, immunity, and accident or chance [7]. These items were also tested by the authors for construct validity in the current sample of patients with BEB and HFS. Four constructs were identified: psychological attributions, risk factors, lifestyle, and chance. Higher scores on each subscale indicates stronger beliefs the condition was caused by these factors.
The internal consistency of the new IPQ-R subscales was found to be high (Table 2), with the exception of the chance subscale (α=0.18). When the item relating to “accident or injury” was removed a satisfactory Cronbach’s alpha of 0.50 was achieved for this subscale (Table 2).
Treatment beliefs
Beliefs about BTX were measured using the Treatment Representations Inventory (TRI) [9]. This 27-item measure consists of four scales measuring treatment value, treatment concerns, decision satisfaction and cure, with higher scores representing stronger beliefs in these areas. This measure demonstrated good internal consistency in the current sample when tested by the authors, with Cronbach’s alphas ranging from 0.67 for the cure subscale to 0.86 for the decision satisfaction subscale (Table 2).
Quality of life
Quality of life was measured using the Craniocervical dystonia questionnaire (CDQ-24;[22]), which has been used successfully in BEB and HFS [23]. The CDQ-24 assesses adjustment in five life domains: emotional well-being, activities of daily living, social/family life, pain, and stigma. Raw subscale scores were linearly transformed to a 0-100 scale, with higher scores indicating poorer quality of life.
Statistical analysis
All analyses were undertaken using IBM SPSS Statistics Version 22.0.
Missing data
Missing data was dealt with using mean imputation methods. Where over 50% item-level data were missing the subscale score was considered missing. If over 50% total data were missing for a single participant their data were not analysed.
Relationships between factors
Correlations between illness perceptions (IPQ-R), treatment perceptions (TRI), quality of life (CDQ-24), disease severity (JRS), and disability (BSDI) were assessed using Pearson’s product-moment correlation. Where data were not normally distributed, Spearman’s rho was used.
Group differences
Comparisons between the beliefs of patients with BEB and HFS were made using independent samples t tests. Non-parametric Mann Whitney U tests were used for any subscale that was found to be non-normally distributed.