Validating a short-form strategy inventory for English as a foreign language learners: testing Oxford's strategy role flexibility theory.

Patients receiving maintenance hemodialysis (MHD) frequently experience oral complications secondary to renal failure, including halitosis, xerostomia, and oral mucosal lesions, which may impair masticatory and swallowing functions (). Previous studies have reported that the prevalence of moderate-to-severe periodontitis, thirst, oral pain, and ammonia-related halitosis among individuals receiving MHD may reach 93.3, 68.9 to 86%, 72, and 53.3%, respectively, which are significantly higher than those observed in the general population (, ). These oral health problems are particularly pronounced among older adults receiving MHD and have been shown to exert substantial effects on physical, psychological, and social functioning (, ). The process of aging is associated with physiological atrophy of the salivary glands, diminished manual dexterity, and a higher incidence of polypharmacy (encompassing antihypertensives, anticholinergics, and calcium channel blockers). All these factors exacerbate xerostomia and undermine oral self-care (, ). Moreover, cognitive decline may lead to reduced compliance with proper toothbrushing techniques. When combined with end-stage renal disease (ESRD), these age-related alterations impose a distinct and severe burden on oral health. However, the interaction among aging, dialysis-related factors, and oral health remains inadequately investigated. Oral health-related quality of life (OHRQoL) is a patient-centered outcome measure that evaluates the physical, psychological, and social implications of oral conditions (). It is commonly assessed using validated instruments such as the Oral Health Impact Profile-14 (OHIP-14). Although OHRQoL has been investigated in general populations with mental health disorders (), three significant research gaps remain. First, most existing studies have included patients across all age groups. Despite age-related physiological changes that influence oral health, age-stratified data specifically for older adults (aged ≥60 years) are limited. Second, oral self-efficacy—a crucial psychological determinant of health behaviors—has not been sufficiently explored, even though it is known to predict oral hygiene practices and outcomes in other chronic disease populations (). Third, the independent contribution of objective biochemical markers (e.g., pre-dialysis blood urea nitrogen [BUN] and serum creatinine) to OHRQoL, after accounting for self-efficacy and oral hygiene behaviors, remains unclear. Elevated levels of BUN and creatinine reflect the accumulation of uremic toxins, which can alter oral microecology and lead to ammonia-related halitosis, potentially affecting social interactions and quality of life (). Furthermore, diabetes—a major comorbidity in patients receiving MHD—has well-established bidirectional associations with periodontitis and systemic inflammation; however, its independent effect on OHRQoL in older MHD patients has not been fully elucidated.