We examined the associations between frailty and healthcare utilisation in different public healthcare settings in Singapore and the results showed that the association between frailty and healthcare utilisation varies in different settings. While the frail elderly in the community had significantly higher proportion and number of SOC visits, ED visits, day surgery and hospitalisations in the 6-months before and after the baseline, their utilisation of public primary care services was lower relative to their pre-frail robust peers.
Prior studies consistently reported that increasing frailty is associated with substantial increases in hospital admissions, measured either retrospectively or prospectively [8, 15, 38]. We also observed that the frail older adults in the study had more hospitalisations than their robust and prefrail peers, regardless whether the hospitalisations incurred before or after the baseline. Their association is persistent even after adjusting for the socio-demographics, multimorbidity and disability status. Among the healthcare service utilisation in the five different care settings, our study found that frailty had the most significant impact on hospitalisations in both 6-months before and after baseline, which is consistent with findings reported in prior studies [8, 11, 39]. The association between frailty and hospitalisations reflects that frail elderly in Singapore tend to present to the healthcare system, especially tertiary care, when they are in a more severe stage of frailty .
Although the association between frailty and healthcare utilisation of specialist outpatient care is less investigated compared with that of inpatient services, prior studies do suggest that frailty has positive association with the use of specialist outpatient services [8, 41]. Our study provides additional support for their association, regardless whether the SOC visits incurred 6 months before or after the baseline. This reflects that an increase in the severity of frailty among older adults corresponds with a greater need for comprehensive and specialised health care services [41, 42].
Unlike prior studies which reported that frailty had a positive association with probability of use of primary care services in general practitioner clinics [8, 14, 15, 39], our study found frail individuals did not have higher risk of utilising more polyclinic services than their robust counterparts. Instead, the older adults who were in the prefrail stage tended to use more polyclinic services. This suggests that when older adults deteriorate from robust health state to prefrail stage, their use of primary care services increase significantly; and when older adults are in a more severe stage of frailty, their needs may shift towards increased specialist care services. However, the results should be interpreted with caution as only about 20% of the total primary care services in Singapore are provided by polyclinics. The omission of private general practitioner utilisation data in the RHS database made it challenging to infer the association between frailty and total primary care utilisation. This might partially explain why frail individuals did not report higher primary care visits compared to their robust or prefrail counterparts, although polyclinics provide a larger percentage of care for patients with chronic and more complex conditions compared to private general practitioners.
Strengths and limitations
To the best of our knowledge, this is the first study investigating the association between frailty and patterns of healthcare utilisation in different care settings in Singapore. We examined the association using both retrospective and prospective utilisation data and found consistent relationship between frailty and healthcare utilisation in respective settings.
The analyses presented in the study used number of hospitalisations to capture the inpatient utilisation. Although number of hospitalisations is a partial indicator of inpatient utilisation, length of stay, which also reflects another important aspect of inpatient utilisation , was not measured.
The healthcare utilisation data were derived from regional healthcare system, as such, healthcare utilisation in other RHS, private general practitioners, private specialist clinics and hospitals, as well as home care services provided by Voluntary Welfare Organisations were not included. This may cause under-estimation of the association between frailty and healthcare utilisation. However, as the participants were the residents in the region with their health entrusted to the NHG RHS, the majority of their utilisation in public healthcare services should have been captured and serve the purpose of understanding the patterns of service delivery for older people with different frailty status in these five healthcare settings within the defined geographical region served by the NHG RHS.