Health of Spanish centenarians: a cross-sectional study based on electronic health records

The substantial decline in old age mortality of the past decades, together with the large birth cohorts of the early 1900s, has led to more and more people currently living beyond 100 years worldwide [1]. The United Nations, which monitors the global number of centenarians since 1990, stated that this age group will strongly increase from half a million in 2015 to more than 25 million people in 2100 [2]_. In Spain, their numbers are estimated to increase from 16,460 at present to more than 220,000 in 2066 [3].

Additionally, the rates of multimorbidity (i.e., presence of two or more chronic diseases) [4] and of its associated negative consequences such as higher risk of polypharmacy, disability and functional decline, and inappropriate healthcare use (e.g., hospitalizations by ambulatory care sensitive conditions, readmissions to hospital in a short period of time, overutilization of healthcare services) [5] could be expected to increase in centenarians as the burden of chronic diseases consistently grows with age [6‐8]. Notwithstanding, centenarians have been described as a heterogeneous population group in terms of their morbidity profiles [9, 10] and health service use patterns [11], which might be explained in part by the dissimilar populations and methodologies used in the existing literature [12‐14].

Some studies suggest that the burden of chronic conditions in centenarians is low, with low lethality rates [10, 15, 16] and low healthcare use [17]. Richmond et al. [16] conducted a study based on structured health history questionnaires and reported a relatively low prevalence of chronic conditions, with many centenarians escaping cardiovascular disease, osteoporosis, dementia, respiratory illness, cancer, anxiety and depression. However, the positive results reported by Australian centenarians might be related in part to the fact that this study was based on self-perceived health information from a convenience sample with various recruitment methods. By contrast, the Danish Centenarian Study [9] showed high levels of morbidity, particularly in hypertension (52%), dementia (51%), ischemic heart disease (27%), and strokes (22%); and a study of Tokyoite centenarians [18] found that more than 95% of them had chronic diseases.

The most commonly reported diseases in centenarians vary among studies and countries, including chronic conditions and symptoms such as joint pain (64%), hypertension (40–64%), cataracts/ocular disease (47–71%), arthritis (58%), left ventricular dysfunction (54%), heart disease (29–31%), osteoporosis (28%), gastrointestinal disease (21%), depression (18%), and cerebrovascular disease (16%), and also conditions such as fractures (47%) and dizziness (44%) [16, 18, 19].

Understanding the health profile and health care needs of the very elderly and generally frail, such as centenarians, becomes especially relevant when considering their numbers are increasing exponentially. Although the more methodologically sound research studies reported high prevalence of chronic diseases and multimorbidity in centenarians, no studies on the health status or healthcare use of Spanish centenarians have been published in the English literature. With our data including almost all centenarians in a geographical region that is representative of the whole of Spain we expect to provide sound scientific knowledge to this field of study. This could facilitate the design of specific care models fitting the socio-demographic and clinical characteristics of centenarians, and the identification of potential underlying factors for shorter longevity. The aim of this study was to describe the socio-demographic, clinical and healthcare use characteristics of a cohort of Spanish centenarians using routinely collected data from electronic health records and clinical-administrative databases.

This study describes the socio-demographic, clinical and healthcare use characteristics of 1680 Spanish centenarians of the EpiChron Cohort between 2011 and 2015 based on electronic health records and clinical-administrative data sources. As far as we know, this is the first study describing the health status of Spanish centenarians in the English literature using register-based health record data from a population-based cohort. As expected, the vast majority of people who reached age 100 were women [26].

Multimorbidity prevalence has been shown to increase as we get older [23, 27]. This concurs with the results from the EpiChron Cohort, where multimorbidity prevalence increased from 12% in the population aged 0–14 years to 16, 47, and 80% in people aged 15–44, 45–64 and ≥ 65 years, respectively [20]. According to this trend, one might have expected multimorbidity prevalence in centenarian populations to be above the 80% observed in the present study. However, our results do not necessarily indicate a lower-than-expected burden of chronic diseases, and could just signify physical and/or environmental difficulties in accessing health care services, or a ‘laissez-faire’ attitude or ageism [28] that could ultimately result in lower diagnosis rates.

Medical literature regarding the prevalence of centenarians without a diagnosis of common chronic conditions is inconsistent. In the Danish Centenarian Study [9] the authors found that only one out of 207 subjects was free of actual diseases or chronic conditions. A Japanese study found it to be less than 3% [18], another study reported that 19% of centenarians did not present chronic diseases [10], and yet another study found that 23% of centenarians reached age 100 with no major chronic diseases [29]. The proportion of disease-free centenarians in our study (6%) is within this range, nonetheless, these figures should be interpreted with caution, since previous studies apply varying methodologies and approach sample recruitment and condition analysis differently. In our study, we used a comprehensive list of more than 100 diseases, in contrast with the lists used by other authors [10, 29]. Additionally, data sources were of great importance when interpreting the results. Electronic health records offered an objective method of patient clinical characterization through the diagnosis of previously confirmed medical conditions by healthcare professionals. Nevertheless, although the public health system in Spain provides universal coverage, the absence of registered clinical information does not necessarily mean an absence of disease. Furthermore, health care service use for diagnostic or therapeutic purposes may have been rejected by a number of centenarians. In the Danish Centenarian Study [9] all participants (including proxies) were visited at their domicile for an interview, and further health information was retrieved from medical files and national health registers.

The most frequent diseases observed in centenarians vary among studies. The high prevalence of cardiovascular diseases found in our study is, however, a common finding, and has also been reported in 72 and 40% of Danish and New England centenarians, respectively [9, 10]. Some of the diseases from the cardio-cerebrovascular disease pattern showed by our centenarians (i.e., hypertension, heart failure, cerebrovascular disease, and cardiac arrhythmia) have also been reported in other studies as the most prevalent in this age group. Hypertension prevalence was similar in Spanish, Danish and Japanese centenarians [9, 18], while heart failure prevalence was lower in our study compared to that reported by Danish and Canadians [9, 17]. Cardiovascular and cerebrovascular diseases are the only frequent conditions in our study that associate high mortality rates [10, 15]. The prevalence of diabetes mellitus in our centenarians (11%) was similar to the 6–10% reported by other authors despite using different methodologies [9, 10, 18]. High dementia prevalence is also a common finding in centenarians [30], especially in women [17], whereas chronic ulcers of the skin are more likely to be a consequence of prolonged limitations in mobility as a result of underlining disorders.

According to our findings, one in two centenarians was polymedicated. The most frequently dispensed medications were similar to those in a Swedish study of community dwelling centenarians [31]. The proportion of individuals in our study with no drug prescriptions (7%) was similar to the 5% found in the Danish Study [9]. A study conducted in the United Kingdom (UK), with an observation period of over twenty years using a Primary Care database of 11,000 individuals who reached the age of 100, reported that 27% of centenarians had no drug prescriptions [32]. The mean burden of treatment in our centenarians, however, was lower, maybe because we only included chronic medication. It is also worth noting that our centenarians were treated with drugs with a low anticholinergic load. Despite all that, the percentage of individuals receiving inappropriate medication according to the Beers criteria was double when comparing with the UK study [32].

Some of the differences between men and women in our results regarding drug dispensation could be reasonably attributed to gender-related morbidities, while others could suggest unequal treatment of specific conditions (i.e., gender inequalities) [33]. For example, the overprescription of certain drugs, such as anxiolytics and hypnotics, was greater in women than in men, even though there were no significant differences in the prevalence of sleep disorders or anxiety/neuroses when stratifying by sex. Similarly, women were more often treated for pain with stronger analgesics, like opioids, when comparing with men.

Healthcare use in centenarians was lower than expected by age regardless of the level of care analyzed. The relatively low burden of chronic diseases and medications in centenarians resulted, as expected, in less intensive use of medical services [34]. These findings could even suggest a more appropriate pattern of healthcare use in centenarians, who mainly resorted to primary care instead of specialized care, and were not frequent users of emergency services. Our results are similar to those found in a previous study based on administrative health data of 1842 Canadian centenarians, who used primary care, hospital care and emergency services in 95, 18 and 26% of cases, respectively [17]. However, these results should be interpreted with caution as they might be explained in part by physical and/or environmental difficulties faced by these patients in accessing health care services.

The utilization of electronic health records allowed for the characterization of the health profile and healthcare use of Spanish centenarians. Multimorbidity seems to be the rule rather than the exception in this population, which mainly presented a cardio-cerebrovascular pattern including hypertension, heart failure, cerebrovascular disease, dementia, and skin ulcers. Addressing medical care in the very elderly from a holistic geriatric view is critical in order to preserve their health, and avoid the negative effects of polypharmacy. Future studies aimed at characterizing the health profile and longevity determinants of centenarians should also take into account genetic, environmental and socioeconomic factors as well as lifestyle habits and physical functionality.