Patients over 75 years old compose the fastest growing age category of incident dialysis patients. According to the United States Renal Data System registry (USRDS 2011) in 2008 nearly 30 thousand patients aged 75 years + started dialysis therapy in the US, whereas 16 years earlier (1992) the respective figure was around 10 thousand (1).

The same tendency is apparent in Europe, where the mean age of incident patients was 64 years and in such countries as Belgium, France and Italy it was 67 (2).

The fact of the ageing dialysis population is also clearly documented by the latest published epidemiological data on the situation in Poland. Among 5100 dialysis patients who began dialysis treatment in 2009, 53.4% were older than 65 years, and 23% were above over 75 years (3).

In the process of qualification for dialysis treatment, the frequent and severe co-morbidities exhibited by elderly patients should be carefully considered (4). As a consequence of this high burden of co-morbidities, many elderly patients exhibit the features of frailty phenotype, associated with increased risk of falls, disability, hospitalization and death. It leads to functional impairment, i.e. the decreased ability to perform activities of daily living (ADLs) or instrumental activities of daily living (IADLs). The criteria for frailty phenotype include unintentional weight loss, slow walking speed, weakness, exhaustion, and low physical activity.

The evaluation of the activities of daily living takes into account the capability to perform principal self-care functions including: eating, dressing, toileting, maintaining personal hygiene, bed mobility and transfer, and walking. Listed in the instrumental activities of daily living are: medication management, maintaining personal finances, cooking, driving, shopping, telephone use, and care of pets (5).

The available published data clearly show a strong relationship between the prevalence of frailty and the level of renal function (6). In the Dialysis Morbidity and Mortality Study (DMMS) Wave II study the criteria for frailty were met by 67.7% of patients of all ages and according to the age ranges 66.4% (aged 50-60 years) and 78.8% (age > 80 years) (7). Wilhelm-Leen et al. observed two-fold higher risk of frailty in patients with mild CKD and six-fold greater risk with glomerular filtration rate (GFR) < 45 ml/min/1.73 m² (8). Johansen et al. analyzed patients with ESRD; frailty was observed in 44.4% of patients aged < 40 years, 74.2% of those aged 60-70 years, and 78.8% of those older than 80 (9). Among the general population criteria for frailty were met by 7% in those aged > 65 and 40% of those older than 80 (8).

In this context the results of two observational studies are alarming. Kurrella Tamura et al. reported the dismal results of dialysis therapy in a cohort of 3700 nursing home residents of mean age 73.4 ± 10.9 years. During the first three months after starting dialysis over 25% died and a further 33% deteriorated in functional status. At one year after dialysis onset mortality reached 76%, 11% declined in functional status, and only a small minority of 13% maintained the functional status during the whole 12-month observation period (10). Similarly ominous results were published by Jassal et al. in the same issue of the New England Journal of Medicine on loss of independence in patients starting dialysis at 80 years or older. At the time of dialysis initiation the majority of patients (76 of 97, 78%) were living at home with no assistance for the activities of daily living. After half a year 28 patients had died (28.9%), at 2 years after starting dialysis 59 patients had died (61%), whereas of 33 alive (32%) only 11 (11.3%) preserved independence (11).