Understanding Treatment Preferences of Australian Patients Living with Treatment-Resistant Depression

Figures & data

Figure 1 Screenshot of an example of a medication DCE scenario with explanations of the task.

Figure 2 Screenshot of an example of a treatment plan DCE scenario with explanations.

Table 1 Basic Demographics of the Total Sample and Medication DCE Sample

	Characteristic	Total Sample (n=75)	Medication DCE Sample (n=61)
Gender – n (%)	Female	30 (40.0)	26 (42.6)
	Male	45 (60.0)	35 (57.4)
Occupational status – n (%)	Working full-time	23 (30.7)	18 (29.5)
	Working part-time	16 (21.3)	12 (19.7)
	Working casual	9 (12.0)	8 (13.1)
	Not working	14 (18.7)	11 (18.0)
	Home duties and/or caring responsibilities	9 (12.0)	8 (13.1)
	Retired	4 (5.3)	4 (6.6)
Household type – n (%)	Couple with no children	20 (26.7)	17 (27.9)
	Couple family with children	22 (29.3)	21 (34.4)
	One parent family	8 (10.7)	4 (6.6)
	Single person household	14 (18.7)	11 (18.0)
	Group household	10 (13.3)	7 (11.5)
	Prefer not to answer	1 (1.3)	1 (1.6)
Area of residence – n (%)	Metro/city	51 (68.0)	40 (65.6)
	Regional	22 (29.3)	19 (31.1)
	Rural	2 (2.7)	2 (3.3)
Annual total gross personal income (before tax) – n (%)	Nil income	8 (10.7)	7 (11.5)
	<$26,000	26 (34.7)	21 (34.4)
	$26,000-$51,999	20 (26.7)	15 (24.6)
	$52,000-$88,399	17 (22.7)	14 (23.0)
	$88,400 or more	4 (5.3)	4 (6.6)
Annual gross household income (before tax) – n (%)	Nil income	2 (2.7)	1 (1.6)
	<$26,000	9 (12.0)	7 (11.5)
	$26,000-$51,999	15 (20.0)	11 (18.0)
	$52,000-$88,399	21 (28.0)	17 (27.9)
	$88,400-$155,999	19 (25.3)	16 (26.2)
	$156,000 or more	6 (8.0)	6 (9.8)
	Prefer not to answer	3 (4.0)	3 (4.9)

Table 2 Diagnosis and Treatment History Results

	Characteristic	Current Episode (n=71)	Previous Episode (n=4)
Time since first diagnosed with depression – n (%)	In the last 6 months	1 (1.4)	0
	In the last 6–12 months	2 (2.8)	0
	1–2 years ago	5 (7.0)	1 (25)
	2–5 years ago	11 (15.5)	1 (25)
	More than 5 years ago	51 (71.8)	2 (50)
	Do not know	1 (1.4)	0
Diagnosed with anxiety disorders during depressive episode – n (%)	Yes	50 (70.4)	3 (75)
	No	21 (29.6)	1 (25)
Length of depressive episode – n (%)	3–6 months	16 (22.5)	2 (50)
	6–12 months	11 (15.5)	0
	12–24 months	8 (11.3)	2 (50)
	More than 24 months	36 (50.7)	0
Treatments tried during depressive episode – n^a	Antidepressants and medications prescribed for antidepressant effect	69	4
	Other prescription medications	20	2
	Psychological therapy	42	3
	Mindfulness	39	0
	Electroconvulsive therapy (ECT)	7	0
	Transcranial magnetic stimulation (TMS)	6	0
	Lifestyle changes	44	0
	Ketamine/esketamine	1	0
	Other	3	0
Medications tried for at least 6 weeks during depressive episode – n^a	SSRIs (citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, sertraline, venlafaxine)	133	5
	Atypical antipsychotics (aripiprazole, olanzapine, quetiapine)	36	2
	Tricyclic antidepressants (amitriptyline, clomipramine, dothiepin, doxepin, nortriptyline, trimipramine)	35	1
	SNRIs (duloxetine, desvenlafaxine)	29	2
	Tetracyclic antidepressants (mirtazapine, mianserin)	19	1
	Serotonin receptor activity modulators (vortioxetine)	8	0
	MAOIs (phenelzine, tranylcypromine)	7	0
	Noradrenaline reuptake inhibitors (reboxetine)	7	0
	RIMAs (moclobemide)	7	0
	Melatonergic antidepressants (agomelatine)	5	0
	Selective catecholamine reuptake inhibitors (bupropion)	1	0

Note: ^aParticipants may have tried more than one treatment.

Abbreviations: SSRIs, selective serotonin reuptake inhibitors; SNRIs, serotonin noradrenaline reuptake inhibitors; MAOIs, monoamine oxidase inhibitors; RIMAs, reversible inhibitors of monoamine oxidase A.

Table 3 Model Output for Medication DCE

Class Proportions	Symbol	Class 1				Class 2
		0.394				0.606
Utility Parameters		Parameter		SE	T-Ratio	Parameter		SE	T-Ratio
Treatment mode constants
Oral		−0.829		0.508	−1.630	1.376	*	0.331	4.160
Nasal spray		−2.755	*	1.028	−2.680	0.555		0.298	1.860
Infusion		−1.573	*	0.546	−2.880	1.006	*	0.280	3.590
(Reference category: Current treatment)
Effectiveness
Oral
30% improvement		0.830		0.494	1.680	0.556		0.318	1.750
50% improvement		2.019	*	0.500	4.040	0.959	*	0.324	2.960
70% improvement		1.911	*	0.51	3.750	1.238	*	0.343	3.610
(Reference category: 10%)
Nasal spray
30% improvement		0.869		1.202	0.720	1.009	*	0.355	2.840
50% improvement		2.489	*	1.110	2.240	1.343	*	0.338	3.970
70% improvement		3.407	*	1.139	2.990	1.833	*	0.345	5.310
(Reference category: 10%)
Infusion
30% improvement		0.443		0.714	0.620	0.064		0.342	0.190
50% improvement		0.317		0.838	0.380	0.934	*	0.342	2.730
70% improvement		2.173	*	0.737	2.950	1.092	*	0.338	3.230
(Reference category: 10%)
Remission
Oral
10%		0		Fixed parameter		0		Fixed parameter
30%		0		Fixed parameter		0		Fixed parameter
50%		−0.146		0.382	−0.380	0.464		0.280	1.660
(Reference category: 0%)
Nasal spray
30%		0		Fixed parameter		0		Fixed parameter
50%		0		Fixed parameter		0		Fixed parameter
(Reference category: 10%)
Infusion
30%		0		Fixed parameter		0		Fixed parameter
50%		0		Fixed parameter		0		Fixed parameter
(Reference category: 10%)
Risk of weight gain
Oral
5% risk		0.683	*	0.338	2.020	0.047		0.250	0.190
(Reference category: 10–15% risk)
Monthly out of pocket cost
Oral
$120-$160		−1.548	*	0.466	−3.320	−0.125		0.327	−0.380
$200-$240		−1.495	*	0.486	−3.080	−0.337		0.322	−1.050
$280-$320		−1.719	*	0.456	−3.770	−0.367		0.321	−1.140
(Reference category: $40-$80)
Nasal spray and Infusion (Class 1)
$500		−1.976	*	0.563	−3.510	-		-	-
$750		−3.131	*	1.077	−2.910	-		-	-
$1000-$2500		−3.950	*	0.677	−5.840	-		-	-
(Reference category: $100-$250)
Nasal spray and Infusion (Class 2)
$1500		-		-	-	−0.711	*	0.204	−3.490
$2000		-		-	-	−1.004	*	0.288	−3.490
$2500		-		-	-	−1.358	*	0.303	−4.480
(Reference category: $100-$1000)

Notes: *Statistically significant at the 5%-level. Restricted log-likelihood: −1353.023; Log-likelihood: −759.434; McFadden Pseudo R-squared: 0.439; Number of respondents: 61; Number of choice observations: 976. All categorical attributes were dummy coded and should be compared to the reference category. Omitted attributes: frequency of administration, onset of response, risk of dissociation (nasal spray and infusion only), ability to drive the next day (nasal spray and infusion only), risk of blood pressure increase (nasal spray and infusion only), risk of sleepiness or drowsiness (oral only) and risk of headache, dizziness or nausea (oral only).

Figure 3 (A) Attribute importance for medication DCE: Nasal spray. (B) Attribute importance for medication DCE: Infusion. (C) Attribute importance for medication DCE: Oral.

Table 4 Model Output for Treatment Plan DCE

Class Proportions	Symbol	Class 1				Class 2
		0.584				0.416
Utility Parameters		Parameter		SE	T-Ratio	Parameter		SE	T-Ratio
Current treatment plan		−1.189	*	0.340	−3.500	1.697	*	0.443	3.830
(Reference category: Treatment A or B)
Treatment effectiveness
50% improvement		1.368	*	0.231	5.930	0.915	*	0.461	1.980
70% improvement		1.855	*	0.264	7.020	1.093	*	0.470	2.320
(Reference category: 30% improvement)
Medication
Oral pills at home		0.800	*	0.212	3.780	−0.470		0.399	−1.180
Nasal spray in clinic and oral		0.505	*	0.188	2.330	−0.630		0.409	−1.540
Infusion in clinic		0		Fixed parameter		0		Fixed parameter
(Reference category: None)
Brain stimulation
ECT		−0.743	*	0.240	−3.100	−0.521		0.480	−1.090
TMS		0		Fixed parameter		0		Fixed parameter
(Reference category: None)
Primary Healthcare Practitioner
Psychologist		0.438	*	0.188	2.330	0.715	*	0.321	2.230
Psychiatrist		0		Fixed parameter		0		Fixed parameter
(Reference category: GP)
Monthly out of pocket cost
$250		−0.181		0.245	−0.740	0.660	*	0.374	1.770
$500		−0.181		0.245	−0.740	−1.219	*	0.563	−2.170
$750		−0.818	*	0.301	−2.720	−2.704	*	1.055	−2.560
$1000-$2500		−1.398	*	0.254	−5.500	−3.927	*	1.068	−3.680
(Reference category: $100)
Class assignment parameters
Constant		−0.003		0.523	−0.010	0		Fixed parameter
Area of residence
Metro		1.280		0.697	1.840	0		Fixed parameter
(Reference category: regional)
Age
Under 45 years		−1.585	*	0.762	−2.080	0		Fixed parameter
(Reference category: 45 years and older)

Notes: *Statistically significant at the 5%-level. Restricted log-likelihood: −659.167; Log-likelihood: −424.462; McFadden Pseudo R-squared: 0.356. Number of respondents: 75; Number of choice observations: 600. All categorical attributes were dummy coded and should be compared to the reference category. Omitted attributes: remission, psychotherapy, lifestyle changes, mindfulness and treatment setting.

Figure 4 Attribute importance for treatment plan DCE.

Note: Total is not shown because the class assignment model should be used to probability weight the segments based on specific characteristics.