Primary and secondary outcomes will be assessed at baseline, 3, 6 and 12 months (see Table
1). Primary measures are changes in symptom severity of anxiety and depressive disorders as assessed by the Hospital Anxiety and Depression Scale (HADS) [
29]. Secondary measures are: quality of life, as assessed via a disease-specific measure the Kidney Disease Quality of Life (KDQoL) [
30] and health-related quality of life as assessed by the Assessment of Quality of Life (AQoL-6D) [
25] and European Quality of Life-5 dimensions (EQ-5D-3L) [
26] (both scales are highly cited, AQoL with Australian norms allowing comparison); self-efficacy measured by the General Self-Efficacy Scale (GSE) [
31], a general sense of perceived self-efficacy in regarding daily hassles as well as adaptation to stressful life events; illness perceptions measured by the Brief Illness Perception Questionnaire (Brief-IPQ) [
32], an assessment of cognitive and emotional representations of illness; coping strategies as measured by an abbreviated version of the COPE Inventory [
33], the Brief COPE [
34]; a 10-item measure of the Big Five personality dimensions [
35]; and impact of a person’s mental health difficulties on their ability to function via the Work and Social Adjustment Scale (WSAS) [
36]; treatment expectancy and rationale credibility in clinical studies as assessed by the Credibility/Expectancy Questionnaire (CEQ) [
37]; perceived acceptability of treatment, assessed using the Treatment Evaluation Inventory-Short Form (TEI-SF) [
38]; clinical indices such as albumin and haemoglobin levels and Kt/V (dose of dialysis); and health care utilisation for economic evaluation purposes assessed by the Health Care Utilisation Questionnaire (HCUQ) [
39]. Scoring and interpretation of all questionnaires will be undertaken using the recommended published procedures outlined by the relevant questionnaire authors. Adherence to the intervention will be recorded in sessions 2 to 9 by the program facilitators as participants provide feedback on their uptake of the DOHP in the time between each session.
Table 1
Primary and secondary outcome assessments and time points for Dialysis Optimal Health Program (DOHP)
Primary outcomes |
HADS (14 items) | X | X | X | X |
Secondary outcomes |
AQoL-6D (20 items) | X | X | X | X |
Brief COPE (28 items) | X | X | X | X |
Brief-IPQ (9 items) | X | X | X | X |
CEQ (6 items) | | X | | |
Clinical indices (e.g. Kt/V) | X | X | X | X |
EQ-5D-3L (6 items) | X | X | X | X |
GSE (10 items) | X | X | X | X |
HCUQ (17 items) | X | X | X | X |
KDQoL (24 items) | X | X | X | X |
TEI-SF (9 Items) | | | | X |
TIPI (10 items) | X | | | |
WSAS (5 items) | X | X | X | X |
Regarding outcome measurement for the cost-effectiveness analysis the utility measurements of generating quality of life will be assessed using AQoL-6D [
25] developed in Australia and the EQ-5D [
26]. Regarding cost, health care utilisation of the patient will be collected from the medical records at St Vincent Hospital for inpatient use (patient consent obtained) and by self-administered Health Care Utilisation Questionnaire (HCUQ) [
39] for inpatient use other than St Vincent Hospital and all outpatient and community health care use from the patient at baseline and each of the follow-up visits. The sources of the price information are from MBS (Medical Benefit Schedule), PBS (Pharmaceutical Benefit Scheme) and other Australian governmental documents. Both healthcare outcomes and costs will then be compared between participants in intervention and control groups using the incremental cost-utility ratio which indicates the incremental cost per QALY (quality-adjusted life year) of this intervention within the trial period. The estimated long-term (lifetime) impact on cost and effectiveness of the intervention beyond the trial period will be extrapolated using Markov process modelling. The Markov process model will be constructed in reflecting the evolving and progressing of the health state of patients with CKD and ESKD, including the health state of, for example, relapse of depression and anxiety. Appropriate sensitivity analysis for the best and worst scenarios will also be performed based on key variables such as the probabilities of relapse of depression and anxiety to examine the robustness of the cost-effectiveness result.
Due to variability of usual care in the control group, key aspects of standard care will be assessed via responses to the HCUQ [
39]. Medical records will also be accessed to confirm diagnostic information, inpatient, outpatient and emergency department visits.