Some 85.2% of people over 65 years of age in the basic health area had chronic disease, figures similar to those of the National Health Survey of 2017 in Spain, which observed that 89.5% of people aged 65–74 years, 95.2% of those aged 75–84 years, and 96.5% of those aged over 85 years reported some disease or chronic health problem [25]. In other European countries, such as Italy, the figures also resemble those of our study, with 86% of those over 65 years of age having some chronic disorder[26]. These figures are higher than those reported by the National Center for Chronic Disease Prevention and Health Promotion of the United States, where 67.7% of those over 65 years belonging to the Medicare programme had at least one chronic disease [27]. The prevalence of chronic diseases was slightly higher than that observed in other studies that have used the AMG in Spain, such as that of the Chronicity Strategy Evaluation Report, where 77.6% of the population older than 65 years had at least one chronic health problem, a percentage that exceeded 80% in people older than 85 years [17].
This population of chronic patients older than 65 years had a high mean age; almost two-thirds (65.8%) were women; 89.4% had multimorbidity; and almost half (47.1%) were polymedicated. The predominance of women coincided with other series that showed a higher frequency of chronic diseases in women [28–30].
Women older than 65 years had greater immobility, more chronic diseases, and polypharmacy more often than men, as observed by other authors [31, 32]. Anxiety, depression, thyroid disorder, osteoporosis, obesity, high blood pressure, and dyslipidaemia predominated in women, while chronic obstructive pulmonary disease (COPD) and ischaemic heart disease predominated in men, in line with other studies [33, 34].
The mean age of our series was similar to that of other series of chronic patients older than 65 (74.9 years) [28, 35, 36]. Medium and high risk were more frequent in the age group older than 85 years (45% and 19.7%, respectively). High-risk patients presented a higher percentage of functional impairment and immobility than medium- and low-risk patients, which has also been observed in complex chronic patients [31, 35, 37]. More high-risk chronic patients required primary caregivers than medium- and low-risk chronic patients, but fewer than 40% of patients that had primary caregivers in other pluripathological series [31]. One series has reported a 0.4% rate of palliative care among chronically ill patients [38], lower to our data, and it was much more common in the high-risk stratum (6.5%). The mean number of chronic diseases was 2.6 in low-risk, 4.5 in middle-risk, and 7 in high-risk patients. The number of chronic diseases adjusted for age increased with age, as in other series [33, 39, 40]. The most frequent chronic diseases were similar to those in other series, with a cardiovascular, lung, neurological, kidney and osteoarticular disease predominance [34, 41, 42], and they were more severe in high- and medium-risk chronic patients. Polypharmacy was high in high-risk patients (85.4% of patients), which is in line with the 50–94% of other studies [31, 41, 43] and is much higher than that observed in medium- and low-risk patients (59.3% and 28.6%, respectively).
Thus, low-risk chronic geriatric patients have more often a single chronic disease, and medium-risk chronic patients normally are multipathological or multimorbid patients, terms that appear in the literature and that share frequencies and similar characteristics [31, 41]. High-risk chronic patients could be more specifically multipathological patients with functional and fragile deterioration or complex chronic patients, with a reported prevalence of these patients of 1.38-5% [44], similar to our finding.
The contact with PC of these chronic patients older than 65 years was high, similar to that observed in other studies [11, 45]. The mean use of PC health services for these chronic patients was high at all risk levels and was much higher at high risk levels. The majority of contacts were health related and face-to-face, similar to the trend in other studies [11, 45–47]. The mean number of contacts with the family physician found in our study was lower than the mean number of medical consultations in other studies [48]. It was higher than the mean number of contacts with nursing, unlike other previous studies where the mean number of contacts with nursing was higher than the mean number of contacts with doctors[49]. This lower number of contacts with nursing by chronic patients should make us reflect on how care is being given to these patients, since the models of care that are proposed in the strategies for addressing chronicity prioritize care focussed on nursing and directing the intervention of the physician to processes that require medical care or situations of greater complexity [23]. In the same sense, visits to social workers were very rare, but it would be expected that the social care needs of some chronic patients would be higher, although the area covered by the centre overall is an area with good socioeconomic indicators. The availability of only one social worker for several centres can also influence the accessibility to the service. Also noteworthy is the low number of noncontact services and home visits, something that should be promoted in the framework of care for chronic geriatric patients as well as in the COVID-19 pandemic situation[50].
The two sexes had no significant differences in contact with PC despite other studies where was reported greater use of health-care services in women [32]. However, the different age groups did, annual contacts being higher in patients over 85 years of age than others, as is also observed in other studies[8, 11].
The increase in the use of PC services was significantly associated in the multivariate model with older age, high risk level, greater weight of complexity, and a number of chronic diseases ≥ 4, a profile similar to that of the complex chronic patient [31].
Regarding the limitations, on the one hand, the basic health area was a neighbourhood with a medium–high socioeconomic level (MEDEA deprivation index in quartile 1) [22], which can make the population more likely to have double insurance that would reduce the use of health services of the public health system. However, more than 90% of people living in Madrid visited PC in 2015 [34]. The PC diagnostic information provides a good approximation of the morbidity of a population (especially chronic diseases), but it is not 100% complete, and some underreporting should be recognized since the coding of the diagnoses can vary according to the doctor who performs it. Despite all this, we have worked with real-world data, which provided a large volume of information from the population in real clinical practice conditions, overcoming the limitations of studies conducted with surveys or small samples. On the other hand, there are authors who have raised doubts about the transparency and complexity of AMG [51, 52], which has generated a debate on whether this situation is common to the rest of the commercial grouping tools [19, 53]. In addition, AMG has a clinical-healthcare management utility that considers the complexity and morbidity of the patient but does not take into account other factors, such as psychosocial problems. Even so, it has been a useful tool for measuring the burden of disease in PC, and the Ministry of Health aims to apply it to the entire National Health System for the management of chronic patients [16, 19].
In conclusion, almost 90% of the population older than 65 years from the health centre was classified by AMG as chronic. These chronic geriatric patients were stratified by AMG into three risk levels, which presented differences in sex, age, functional impairment, need for care, morbidity, complexity, polypharmacy, and use of PC services. The greatest use of services was by patients with older age, high risk level, greater weight of complexity, and ≥ 4 chronic diseases. Further research is needed to be able to develop an intervention model more adapted to the reality of the geriatric population based on risk levels by AMG.