A power analysis was conducted using G*Power 3.1 software and revealed that the minimum number of participants required to detect main effects of moderate to large effect size with sufficient power (80%) is 52 participants. In the current study we sought to recruit enough participants to be well above this cut-off.
After providing written, informed consent, a total of 70 participants took part: 35 who had suffered a first-time stroke and 35 demographically matched controls. Stroke participants were deemed eligible if they had suffered a first-time stroke, as confirmed via MRI or CT, between 9 and 18 months prior to testing. All stroke participants were recruited following admission to either the Princess Alexandra Hospital or the Royal Brisbane and Women’s Hospital in Brisbane, or via a retrospective clinical file audit at The Mater Hospital. All control participants were recruited via community-based advertising. Table 1 provides detailed demographic and clinical characteristics of the stroke group.
Table 1
Demographic and clinical characteristics of the stroke participants
ID | Age | Gender | Edu. | Hand. | Chronicity (months) | | Neurological details |
| Type | Hemisph. | Artery/vessel | Lesion site |
1 | 52 | M | 13 | R | 15.85 | | Isch. | Left | MCA | Frontal lobe |
2 | 75 | F | 9 | R | 13.34 | | Haem. | Right | Small vessel | Basal ganglia |
3 | 70 | M | 18 | R | 12.12 | | Isch. | Right | MCA | Caudate head, frontal, lentiform |
4 | 67 | M | 15 | R | 11.10 | | Isch. | Left | PCA | Occipital lobe |
5 | 55 | M | 17 | R | 10.67 | | Isch. | Right | MCA | Basal ganglia, superior temporal |
6 | 70 | F | 18 | L | 9.85 | | Isch. | Right | MCA | Parietal, temporal |
7 | 60 | M | 14 | R | 12.22 | | Isch. | Left | PICA | Cerebellum |
8 | 64 | M | 14 | R | 12.55 | | Isch. | Right | PCA | Occipital lobe |
9 | 29 | F | 17 | R | 14.76 | | Isch. | Left | ACA | Frontal |
10 | 68 | M | 18 | R | 11.66 | | Isch. | Right | MCA | Frontal, tempoparietal |
11 | 72 | M | 20 | R | 14.16 | | Haem. | Right | N/A | Prefrontal |
12 | 52 | M | 14 | L | 15.02 | | Isch. | Right | ACA | N/A |
13 | 60 | M | 18 | R | 12.22 | | Isch. | Left | PICA | Cerebellum |
14 | 52 | M | 10 | L | 11.46 | | Isch. | Left | MCA | Frontal, parietal, centrum semiovale |
15 | 59 | M | 18 | R | 12.84 | | Isch. | Right | MCA | Parietal |
16 | 72 | F | 14 | R | 15.35 | | Isch. | Right | N/A | Cerebellum |
17 | 73 | F | 17 | R | 16.89 | | Isch. | Right | PCA | Occipital lobe |
18 | 71 | F | 13 | R | 18.64 | | Isch. | Left | MCA | Frontal, parietal |
19 | 82 | F | 10 | R | 17.75 | | Isch. | Left | MCA | Parietofrontal |
20 | 76 | M | 8 | R | 18.41 | | Isch. | Left | Small vessel | Internal capsule |
21 | 79 | M | 11 | R | 17.34 | | Isch. | Left | MCA | Posterior MCA territory |
22 | 87 | M | 21 | R | 12.96 | | Haem. | Left | PCA | Parietal, occipital |
23 | 58 | F | 11 | R | 14.90 | | Haem. | Left | ACA | Frontal |
24 | 51 | M | 13 | R | 14.34 | | Isch. | Right | SCA, PICA | Cerebellum |
25 | 74 | F | 10 | R | 13.65 | | Isch. | Left | MCA | Parietal |
26 | 46 | F | 18 | L | 15.13 | | Isch. | Left | MCA | Posterior frontal |
27 | 76 | M | 17 | L | 9.94 | | Isch. | Right | MCA | Frontal, parietal |
28 | 57 | F | 10 | R | 13.09 | | Haem. | Right | MCA | Lateral ventricle |
29 | 42 | M | 12 | R | 12.53 | | Isch. | Left | Small vessel | Thalamus |
30 | 52 | M | 13 | L | 12.78 | | Isch. | Right | MCA | Precentral gyrus |
31 | 80 | M | 9 | R | 13.01 | | Isch. | Right | MCA | N/A |
32 | 58 | M | 8 | R | 12.17 | | Isch. | Left | PICA | Cerebellum |
33 | 71 | F | 13 | R | 13.73 | | Isch. | Left | PCA | Cerebellum |
34 | 71 | M | 12 | R | 10.73 | | Isch. | Right | MCA, PCA | Right occipital lobe, right and left pre-central gyrus |
35 | 83 | M | 20 | R | 14.13 | | Isch. | Right | PCA | Lateral pontine, midbrain and cerebellum |
Note. ACA = anterior cerebral artery; Edu = years of education; Haem = haemorrhagic stroke; Hand = handedness; Isch = ischaemic stroke; MCA = middle cerebral artery. PCA = posterior cerebral artery; PICA = posterior inferior cerebellar artery; SCA = Superior cerebellar artery. |
To be eligible, all participants had to be a native English speaker, or have a high level of English proficiency. The stroke and control groups were matched in terms of gender composition (both 56.7% male), and were closely matched in terms of age (M = 64.69, SD = 12.92 and M = 63.23, SD = 9.75, respectively, t(68) = 0.53, p = 0.596) as well as years of education, M = 14.09, SD = 3.72 and M = 14.64, SD = 2.69, respectively, t(68) = 0.72, p = 0.476).
Measures
Participants in this study also completed measures for an unrelated published study [8]. Only measures relevant to the current study are reported here.
The 8-item base module of the Index of Dental Anxiety and Fear ([IDAF-4C; 9]) was used to assess dental anxiety and fear. The eight questions index emotional, behavioural, physiological, and cognitive components of dental fear. This measure has excellent psychometric properties and is predictive of future dental service use and avoidance due to fear. Each item is scored between 1 (disagree) and 5 (strongly agree), with higher scores indicative of greater dental anxiety.
Oral health was assessed using the Oral Health Questionnaire ([OHQ; 10] The OHQ includes ten items that were identified as being most predictive of the World Health Organisation (WHO) diagnostic criteria for decayed, missing and filled teeth. The items provide data relating to oral hygiene habits, use of oral health services, smoking status and disease presence (bleeding gums, mobility, decay, orofacial pain, and halitosis). The total score ranges from 0 to 20, with higher OHQ scores indicative of poorer oral health.
Negative affect was indexed using the Hospital Anxiety and Depression Scale ([HADS; 11]. The HADS is an extensively used self-report scale with sound psychometric properties. It is particularly suitable for use in clinical populations as it omits somatic items that might be attributable to physical illness. The HADS consists of 14 items, seven of which measure anxiety, the other seven depression. Scoring for each item ranged from zero to three, with a sum score range of 0–42. Higher scores are indicative of greater negative affect.
Quality of life was assessed using the World Health Organisation Quality of Life Scale ([WHO QOL-BREF; 12], an extensively validated 26-item self-report measure, that indexes four domains: physical health (seven items), psychological health (six items), social relations (three items), and environment (eight items). The remaining two items provide an overall rating of subjective satisfaction with health, and quality of life. Scores for all four domains are summed, with a higher total score indicative of higher quality of life.
Analysis
The clinical and control groups were compared on the measures of dental anxiety, oral health and wellbeing using a series of one-way between-group ANOVAs. In instances where violations of the sphericity assumption occurred, degrees of freedom and p-values were adjusted using Greenhouse–Geisser corrections. Correlational and partial correlations were computed to test correlates of dental anxiety in the stroke and control groups separately. SPSS (version 27.0) was used for all analyses.