published_or_final_version / Surgery / Master / Master of Medical Sciences

　　　Obstructive sleep apnoea (OSA) is the most common sleep-related breathing disorder and is associated with a range of adverse physical, social and psychological outcomes that affect quality of life (QoL). Two systematic reviews of the literature (part of this thesis work) found there is conflicting evidence of how different mandibular advancement device (MAD) designs features may affect clinical and subjective OSA outcomes in certain patients. Therefore, a randomized cross-over trial was conducted. Firstly, the correlation between clinical OSA indicators and QOL was explored among patients referred for OSA treatment using MADs. In addition, associations of OSA risk factors, dental status and demographic variables with clinical OSA indicators and QoL indices were determined. Secondly, the efficacy of two different MADs in the treatment of adult OSA patients was assessed and compared. Thirdly, the efficacy of the two MADs in the treatment of adult OSA patients from the subjective perspective of their bed partners was determined. 　　　A consecutive sample of 45 adult OSA patients referred from Queen Mary Hospital Sleep Centre to the Prince Philip Dental Hospital for oral appliance therapy was recruited and treated with a monobloc MAD and a twinblock MADs for a period of 3 months per MAD (cross-over randomised trial). Changes in clinical OSA outcomes were assessed by polysomnography (PSG) and changes in subjective outcomes by the disease-specific Sleep Apnoea Quality of Life Index (SAQLI) questionnaire, the Functional Outcome of Sleep Questionnaire (FOSQ) and Epworth Sleepiness Scale (ESS). Patient compliance, side-effects and MAD preference, as well as MAD treatment impact on the patients’ bed partner was also assessed. At baseline, some clinical OSA indicators, subjective QoL and certain OSA risk factors were significantly correlated (p<0.05). There were significant variations in clinical OSA indicators and subjective QoL indices with respect to certain risk factors (p<0.05), demographic variables (p<0.05) and dental status (p<0.01). 　　　There was a significant difference in favour of the monobloc MAD in terms of improving the apnoea-hypopnoea index (AHI) (p<0.05) and oxygen desaturation index (ODI) (p<0.01). Significantly more patients achieved clinical treatment success with the monobloc compared to the twinblock (p<0.05). Both MADs were efficacious in improving patients’ SAQLI score (p<0.01), FOSQ score (p<0.01) and ESS score (p<0.01). Significantly more patients achieved QoL treatment success with the monobloc (p<0.05) compared to the twinblock. More patients were ‘very satisfied’ with the monobloc treatment (p<0.05) and 63% preferred it to the twinblock. 　　　 No significant difference was found between patients’ and bed partners perceptions of symptom improvement post treatment, however, the monobloc resulted in a significant reduction in bed partners’ daytime sleepiness (p<0.01) and allowed significantly more co-sleeping at night (p<0.05). 　　　 　　　This study concluded that the monobloc is superior in improving subjective QoL and clinical OSA indicators. The monobloc was the preferred MAD and patients were more satisfied with it; bed partners rated this MAD as superior in improving their own daytime sleepiness and co-sleeping. / published_or_final_version / Dentistry / Doctoral / Doctor of Philosophy

Poor adherence to continuous positive airway pressure (CPAP) treatment in patients with obstructive sleep apnoea (OSA) limits its therapeutic effectiveness and has a major impact on clinical outcomes. Effective education programme is important to enhance CPAP use. However, existing education programmes are either manpower or resource demanding and may not be feasible in clinical practice. Moreover, the Self-Efficacy Measure for Sleep Apnoea (SEMSA) has been widely adopted for assessing adherence-related cognitions on CPAP therapy in OSA patients, but it was not available for Chinese. The aims of this thesis are: (i) to perform linguistic and psychometric evaluation of a Chinese version of SEMSA (SEMSA-C); (ii) to examine the efficacy of brief motivational enhancement education programme in addition to standard care versus standard care only on improving adherence to CPAP treatment in patients with OSA. The SEMSA-C was obtained after the standard forward-backward translation process. A randomised controlled trial was then conducted on newly diagnosed OSA patients. Patients in the control group received standard care (SC) comprising advice on the importance of CPAP therapy and its care while those in the intervention group received SC plus motivational enhancement education programme (ME). ME focused to enhance subjects’ knowledge, motivation and self-efficacy to use CPAP, comprising one 45-minute session on the day after CPAP titration and one 10-minute telephone follow-up shortly after commencing CPAP treatment. Epworth Sleepiness Scale (ESS), SEMSA-C, and quality of life were assessed. CPAP usage data were downloaded at the completion of this 3-month study. The primary outcome was the CPAP adherence. Furthermore, 21 patients were randomly sampled at baseline and completed the SEMSA-C at one week. 100 patients (Men : Women, 84 : 16) with OSA indicated for CPAP treatment were recruited, with an average age of 52±10 years, and apnoea hypopnoea index (AHI) of 36.2±22 events/hour. Factor analysis of SEMSA-C identified three factors: risk perception, outcome expectancies and treatment self-efficacy. Their corresponding internal consistency was high with Cronbach’s alpha >0.88, which were larger than all correlations between subscales (Range: 0.14 to 0.58). The correlations between items and their hypothesized subscale (Range: 0.58 to 0.85) were generally higher than the correlations between items and their competing subscales (Range: -0.10 to 0.58). One-week test-retest intra-class correlation ranged from 0.70 to 0.82. CPAP adherence was associated with outcome expectancies and treatment self-efficacy at 3-month assessment. Furthermore, SEMSA-C demonstrated an improvement in self-efficacy (standardised response mean = 0.33, p = .044) but no significant changes were observed in the other two factors, after CPAP use. The 100 patients were followed for 3 months. The interventional effects maintained during the 3-month study period. There were a better CPAP use [higher daily CPAP usage of 2 hours/day (Cohen d = 1.33, p < .001), four-fold the number of subjects using CPAP for ≥ 70% of days with ≥ 4 hours per day (p < 0.001)], and greater improvements in ESS by 2.2 (p = 0.001) and treatment self-efficacy by 0.2 (p = 0.012) in the intervention group, relative to the control group. The traditional Chinese SEMSA-C possesses satisfactory psychometric properties. It is a reliable and responsive instrument to measure perceived risks, outcome expectancies and treatment self-efficacy in Chinese patients with OSA. Moreover, the newly developed brief motivational enhancement education programme in addition to standard care is effective in improving adherence to CPAP treatment, treatment self-efficacy and daytime sleepiness. / published_or_final_version / Nursing Studies / Doctoral / Doctor of Nursing

Thesis (M.Nurs.)--University of Hong Kong, 2008. / Includes bibliographical references (p. 112-122)

Thesis (M.S.) -- Central Connecticut State University, 2008. / Thesis advisor: Ruth Rollin. "... in partial fulfillment of the requirements for the degree of Master of Science in Biology." Includes bibliographical references (leaves 39-41). Also available via the World Wide Web.

Thesis (M. Orth.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 125-144, 225-227).

Thesis (M.Orth.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 125-144, 225-227). Also available in print.

Thesis (M. Phil.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 92-103).

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 83-99).

Thesis (Ph. D.)--Pennsylvania State University, 1996. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.