Among Norwegian elderly > 65 years seeking formal assistance for the first time, we found that 62.1% were frail, 29.3% were prefrail and 8.6% were non-frail according to FFP. We did not find many studies reporting on prevalence of frailty in this population. A frailty prevalence of 54% has been reported in an Irish study, using Clinical Frailty scale among elderly ≥ 65 years who received regular guidance from a public nurse in their home (35). Using Clinical Frailty Scale, 41.5% were found to be frail among elderly receiving low level home help (< 5 hours/week) in another Irish study (36). Finally, 89.9% were classified as frail, according to abbreviated CGA, among older home care clients in Finland (37). Although these studies have different frailty assessment tools and designs, they indicate that the prevalence of frailty among home-dwelling elderly who receive formal assistance, is major.
The results in the present study indicate that screening for frailty should be performed when elderly seek formal assistance for the first time. Firstly, a screening program for this population will be aimed at a population with high a likelihood of being prefrail or frail. Secondly, since early stage in the frailty process can be clinically silent (13), a screening of this population may enable the public health care system to tailor person-centred interventions that may prevent, delay or reverse the condition before onset of physical and/or mental disability (6, 7, 38). This is important since frailty represents a significant burden for the person, next of kin, and the public health care system (5, 13, 17). The best therapeutic time window for preventing and treating frailty is not clear, though detection is necessary for planning and designing person-centred treatment and care plans also for advanced stages of frailty (9). Approaching frailty with comprehensive geriatric assessment (CGA), making individualized care plans based on person-centred interdisciplinary collaboration, may lessen the disability or mitigate the impact of functional impairment for frail elderly, their next of kin and the public health system (8, 39).
The ideal setting or time for frailty screening programs for elderly might be an issue for further research. Our study indicates that some elderly do not ask for formal assistance before they have developed frailty. It may be conceivable that a request for formal assistance comes as a result of decreased physical resilience or frailty development. It is suggested that frailty indicates a person’s “biological age,” rather than chronological age, and that it does so with a high degree of precision (40). This may explain the lack of association between frailty and chronological age in this population, even though there is a clear association between frailty and age in community studies (32). There were more women than men in our cross-sectional study, showing that more women applied for formal assistance in the project period. We assessed a not statistically significant greater proportion of the men to be frail. Frailty is, however, more frequent in women than men in community-dwelling populations (32, 41). This may indicate a behavioural difference between women and men when it comes to applying for assistance. More research is needed to explore this subject.
The second aim of this study was to examine the association between SPPB and GS and FFP. We did find a decreasing trend in both GS and SPPB from non-frail to prefrail and frail group. Associations were found between decreasing GS/SPPB and increasing numbers of criteria for frailty phenotype. The inverse association between GS and increasing numbers of criteria was also statistically significant when accounting for the impact of SPPB-score, but the inverse association between SPPB-score and increasing numbers of criteria was not significant when accounting for the impact of slow usual gait speed.
When comparing test accuracy to detect frailty for GS < 0.8 m/s, SPPB < 10 and SPPB < 7, respectively, we found that all three tests had acceptable positive predictive values (0.76–0.84). GS < 0.8 m/s had the highest sensitivity (0.99) and lowest specificity (0.37), while SSSP < 10 had fair sensitivity (0.82) and highest specificity (0.84).
According to our results, both GS and SPPB appear to be useful tools for screening of FFP among home-dwelling elderly seeking formal assistance for the first time. GS may be superior having higher sensitivity. Castell et al. (2013) found that GS < 0.8 m/s had 0.99 sensitivity and a 0.64 specificity to detect FFP (31). These results are the basis for the recommendation to assess GS to detect frailty in British primary care, where it is recommended that those who test positive should be followed up by a holistic medical review or CGA (12). SPPB may have fair to moderate agreement with FFP to detect frailty (42), though it is developed to assess lower-extremity function (27). It is accentuated that frailty and disability often co-occurring, even though they represent theoretically distinct domains that are not interchangeable (9, 38). Both in the present study and in previous research there are frequent co-occurrences between lower SPPB-scores and FFP, though the frail group according to FFP does not completely overlap the group having SPPB < 7 (20, 42). This may indicate that FFP and SPPB measure different domains. In addition to the high sensitivity of GS < 0.8 m/s to detect frailty, the present study found a statistically significant association between lower GS and increasing numbers of criteria for FFP (p < 0.001), also when adjusting for SPPB-score. This may implicate an association between lower GS and frailty. This is in line with increasing evidence that GS alone can be considered as a valid, reliable and sensitive tool for monitoring functional status and overall health for elderly (28). There is also increasing evidence that underlying causes to slowness may be related to impairment of multiple physiological systems (29, 43), a description which corresponds with the overall understanding of frailty. As both SPPB and GS are inter-reliable tests when conducted by a trained physical therapist (23, 44), the present study may implicate that involving physical therapists in screening programs to detect frailty could be reasonable.
The present study generates novel and valuable knowledge about frailty in a group of elderly that has previously not been investigated. At the individual level, the knowledge is valuable since identifying frailty enables an action to prevent or delay disability. Also, identifying frailty may provide municipalities with information about their population which enables them to better allocate their resources, planning and development of health care.
A limitation of the presents study, can be linked to a relatively small sample size, i.e. the non-frail group in this study consisted of 10 persons only. Estimates for test-accuracy to detect prefrailty in the present study would thus be inappropriate. However, the clinical implications of having a simple test to detect prefrailty, could be important in order to delay consequences of frailty. Firstly, the transition between frailty status is more common between prefrailty and non-frailty than between frailty and non-frailty (6). Secondly, prefrailty may be more useful than frailty to identify patients at risk of losing their functional capacities (45).