- 1 A) OF THE CHRONIC DISEASE TO THE PATIENT IN SITUATION OF CRONICITY
- 1.1 1. Definition of chronic patient
- 1.2 2. Radiography of chronicity in Spain
- 1.3 3. The impact of chronic disease on the patient
- 1.4 4. Impact of chronicity for the Health System
- 1.5 5. Prevention of chronic disease
- 1.6 6. Need for partnerships between professionals, patients and institutions
- 2 B) A NEW PATIENT MODEL: THE ACTIVE PATIENT
- 3 C) HEALTH CARE FOR CHRONIC PATIENTS IN SPAIN: SURVEY OF PATIENTS
A) OF THE CHRONIC DISEASE TO THE PATIENT IN SITUATION OF CRONICITY
The increase in life expectancy, improvements in public health and health care and the generalization of unhealthy lifestyles – smoking, inadequate diet, sedentary lifestyle – have made chronic diseases the dominant epidemiological pattern in Spain. In addition to their personal impact on patients and caregivers, they have an economic impact on families, communities and society. And they also cause a growing demand for services to the National Health System, which translates into greater use of health resources.
All this places the SNS in the face of a huge challenge, which can no longer be faced from the traditional perspective of individual attention to acute diseases. The approach to chronicity requires another broader approach, with new action variables that take into account prevention, comprehensive care, care continuity and the role of the patient himself. In short, a new approach will focus on the person and not on the disease and that will give more importance to “care than to cure.”
On the other hand, the same concept of the chronically ill has changed in recent decades. It is no longer the person with a single disease, but the patient with several chronic diseases, disability, loss of autonomy and clinical fragility. Now there is a direct relationship between chronicity and dependence and, in addition, chronicity is associated with the consumption of health resources, which endangers the sustainability of the social protection system itself 1 .
1. Definition of chronic patient
Chronic patient is a person who suffers from one or several chronic diseases. The World Health Organization (WHO) defines them as “long-term conditions” (more than 6 months) “with a generally slow progression” 2 and highlights four main types:
- Cardiovascular diseases, such as myocardial infarctions and strokes.
- Chronic respiratory diseases, such as chronic obstructive pulmonary disease and asthma.
- Diabetes 2 .
However, there are other health entities that speak of chronicity as of three months and include a greater number of diseases 12 . Diseases that, regardless of when they start, are already for life. Although they vary between them and present multiple forms, including their onset, their characteristic symptoms and their course in time 12 .
For example, Z Hospital Barometer, published in 2015 and carried out in Spain, identifies a total of 28 chronic diseases, including Alzheimer’s, hepatitis, osteoporosis, psoriasis… 13
In what they all agree is that the objective is not in itself to cure these chronic processes, but to take care and prevent their complications since they are slow processes in their progression but maintained over time and without the possibility of spontaneous resolution. This often limits the function, productivity and quality of life of people who live with them 12 .
And these processes have multiple consequences that translate mainly into health problems for the affected people and sometimes even those around them. Problems ranging from physical (functional impairment) to mental health (emotional stress, depression, anxiety) to those of a social nature (social functional impairment) 12 .
All this translates into a lower quality of life for the chronic patient. In fact, people with chronic diseases report poorer rates in areas such as physical function, fatigue, pain, emotional distress and social function than people without these diseases. And in turn, those with two or more chronic diseases have a worse score than people with a single chronic process 12 .
a) Differences with the acute patient
Acute conditions are severe and sudden at the beginning, which could describe anything from a fractured bone to an asthma attack. The chronic condition, on the other hand, is a long-standing syndrome, such as osteoporosis or asthma. The difference between acute and chronic conditions can be observed with very specific examples. Osteoporosis, for example, is a chronic condition, but it can cause a broken bone, which is an acute condition. Conversely, a first asthma attack can lead to a chronic syndrome if it is not treated in time. And then, when chronic asthma has already been diagnosed, there may be acute asthma attacks 3 .
2. Radiography of chronicity in Spain
Any radiography of chronicity is centered on population aging, clearly associated with chronic pathologies and the use of health resources. And Spain, together with Italy and Japan, leads this process worldwide: it is estimated that in 2050, about 35% of our population will exceed 65 years. Before, by 2030, it is expected that chronic diseases will double their current incidence in people older than 65 1 .
One of the consequences is the rapid increase in patients with several chronic diseases. The Spanish National Health Survey of 2006 pointed it out: people aged 65-74 registered an average of 2.8 chronic problems or diseases; above 75 years, the average rose to 3.23 1 .
The trend was confirmed in the European Health Survey of 2009: in Spain, 45.6% of the population over 16 suffer from at least one chronic process (46.5% of men and 55.8% of women), and 22% two processes or more; both percentages increase with age 4 .
And is that the elderly are not the only ones affected by chronic diseases. There is sufficient evidence of the increase in chronic conditions in children and adolescents since 1960. According to the aforementioned ENS of 2006, among the population under 16, 11.86% have been diagnosed with chronic allergy, 7% of asthma, 0.27% of diabetes, 0.26% of malignant tumors (including leukemia and lymphoma), 1.09% of epilepsy, 2.01% of behavioral disorders (including hyperactivity) and 0.73 % of mental disorders 4 .
Healthcare provides another profile to complete the radiography of chronicity. In Primary Care, up to 40% of pluri pathological patients have three or more chronic diseases, 94% are polymedicated, 34% have a Barthel Index (used to assess physical disability from 10 basic activities of daily living) under 60, and 37% have cognitive impairment. The prevalence of perinatology can be estimated at 1.38% of the general population or 5% in people over 65 years of age 4 .
3. The impact of chronic disease on the patient
Chronic diseases are long-term processes that threaten the well-being of the person and their ability to carry out activities in an episodic, continuous or progressive way for many years of their life. According to the World Health Organization (WHO), not only have chronic diseases emerged as the leading causes of death, but they also represent huge and growing causes of deterioration and disability for people 12 .
According to data from the World Health Organization (WHO), chronic pathologies will cause 73% of deaths in the world in 2020. On that date, it will also account for 60% of the global burden of disease 5 .
In the European region of WHO the figures are even higher: they account for 77% of the disease burden. And although mortality from these diseases decreases progressively, their disease burden is increasing. In the case of Spain, they represent 89.2% of the total disease burden measured in disability-adjusted life years, an indicator that is used internationally to measure health loss and that takes into account the years of life lost due to premature mortality and years lived with disabilities or poor health 6 .
In addition to being a cause of premature death, chronic pathologies cause important adverse effects on the quality of life of the affected patients and have important economic effects and underestimated by families, communities and society in general 5 .
The impact of the disease on the chronic patient is accentuated by its increasingly frequent condition of a patient in a situation of complexity or perinatology. Its main characteristics are: presence of several chronic diseases at the same time; Frequent visits to the hospital – be it for emergencies, outpatient consultations or prolonged average stay income – polymedication; decrease in personal autonomy, with frequent situations of disability and dependence; high use of health and social resources; and additional factors such as advanced age, living alone, poor family and social support, pathology, etc. 7
Polymedication in chronic patients deserves special attention because it is a risk factor. In fact, polypharmacy in the elderly continues to grow, and in Primary Care it is increasingly worrying because the frequency of adverse effects and inappropriate combinations of drugs correlate with the number of drugs taken. In addition, it encourages unpredictable drug interactions, hinders the understanding of the guidelines and facilitates non-compliance 8 .
A final significant impact, from the patient’s perspective, occurs in the family environment. The existence of a chronic patient ‘forces’ to re-adapt to the rest of the members, even with changes in roles and alterations in the dynamics and structure of the family. These changes can be structural (rigid patterns of functioning, modification of family roles, social isolation), evolutionary (there is a moment of transition to adapt to needs) and emotional (adaptation is sometimes based on defense mechanisms that can become pathological, such as overprotection or the ‘conspiracy of silence’). And there are certain family characteristics that favor adaptation, such as flexibility in a reorganization, cohesion in extra family relations and, of course, good communication that facilitates changes 9 .
4. Impact of chronicity for the Health System
The combination of population aging and increased chronic diseases has increased the care burden and the consumption of health resources. It is estimated that 70-80% of the annual health budget goes to people over 65, who use 80% of the total consultations, 60% of hospital admissions and 33% of hospital emergencies 7 .
a) Resource utilization
Overall, chronic diseases account for 80% of Primary Care consultations 4 . And regarding hospitalization in SNS centers, there is clear aging of the admitted population: the average age of the patients in 2010 was 53.9 years, almost four years more than in 2000. 42% of the hospitalizations corresponded to people 65 and older 4 .
The analysis of hospital discharges by disease chapters also makes clear the prevalence of chronic diseases: 14.1% of the cases treated correspond to the circulatory system, 12.1% to the digestive system, 11.5% to the respiratory system, and almost 10% to cancers 4 .
Regarding the use of pharmacological resources, it is estimated that the medication for chronic patients represents at least 59% of those given by prescription, a percentage that in practice is higher because the group of drugs for other diseases includes many chronic medications or continued for long periods 7 .
The greater burden of care and consumption of resources requires a change in the culture of professionals, to work in a team in an effective way and favor an appropriate use of health services and technologies, in particular medicines. It is also essential that patients and healthy people become more aware of their own health and the use of health services and benefits. According to the Sanitary Barometer 2011, this chapter is very improvable: 41.2% said that “with some frequency they are used unnecessarily”, and 29.6% that “there is a lot of abuse” 4 .
b) Medication management
Medication is key in the management of the chronic patient, and in particular due to the problems associated with its frequent polymedication: adverse effects, drug interactions, therapeutic non-compliance, etc. Therefore, it is essential to systematically review the treatment to prevent and detect these risks and to improve adherence to it. It is also important to promote the information and participation of patients and caregivers to achieve good therapeutic compliance 4 .
Disability is not a consequence always present because of suffering from a chronic disease, but it is true that it is a condition secondary to these pathologies. In addition, disability generates greater vulnerability in the situation of the patient, especially as age increases 7 .
In fact, disability rates are increasing due to aging and the increase in chronic pathologies associated with this loss of functionality. According to the Survey on Disability, Personal Autonomy and Dependency Situations of 2008, 8.5% of the Spanish population suffered some type of disability; 59.8% were women 4 .
In parallel to the disability, another important problem may arise, the dependence or need for help to perform the basic activities of daily life. In this regard, the key is in the social context: a person with disabilities can be autonomous if they have resources to help alleviate their situation, or dependent in an environment with barriers and without such resources 4 .
d) Non-face-to-face care
The comprehensive approach to chronicity has in the Information and Communication Technologies a tool of enormous possibilities, both for interprofessional communication and with patients, and to complement face-to-face and non-face-to-face assistance. The key element is the shared Electronic Medical Record, which collects all the assistance, preventive and social information for the correct care of patients. For chronic patients, who need follow-up for years and by different Primary and Hospital Care professionals, this document is essential for quality care 1 .
The use of ICTs can be especially useful for promoting new relationship strategies between professionals and chronic patients based on self-care. For example, they allow a closer and more personalized follow-up through the so-called gadgets , telemedicine devices that send some analytical results from the patient’s own home 10 .
Non-face-to-face care has great possibilities for development in Spain, which records the highest rate in Europe in Primary Care consultations (eight visits per person per year) with a control of chronic pathologies similar to other countries where the health center is less visited. ICT can improve this control without increasing the number of visits and make the patient feel well informed and attended without the need for such continuous personal contact. There are already experiences that will change our current concept of visit in the immediate future, with new models such as electronic Internet consultation, telephone consultation or permanent monitoring through so-called gadgets, devices that send analytical results (blood pressure, blood glucose capillary, degree of anticoagulation, electrocardiogram, etc.) to web pages of continuous registration where the professional can remotely perform personalized monitoring of the patient 1 .
It is, in short, to take advantage of different channels (telephone, electronic messaging, SMS, websites) to share information (symptoms and signs, results, tips, reminders) for the benefit of faster, cheaper and more comfortable assistance that allows to detect complications and exacerbations at the same time, the patient’s own confidence in his self-care is boosted 11 .
e) The role of the patient in the transformation of the health system towards the improvement of chronicity care
All strategies on chronicity underline the need to reorganize the health system to adapt it to the needs of the people affected and improve their care. They also coincide in the key role of the patient in this transformation and in the care of their own health 4 .
People with chronic pathology should receive support to favor their self-management of the disease, especially in cases of less complexity where it can be more effective. In those of greater complexity and/or pluripatology, comprehensive management of the case as a whole is necessary, with fundamentally professional care aimed at patients and their care environment 4 .
The ultimate goal is to move from a model in which the patient and the system are passively related to another proactive relationship, where there is also a coordination between levels and care sectors.
5. Prevention of chronic disease
The most prominent chronic diseases are related to common health determinants (tobacco consumption, harmful alcohol consumption, inadequate diet, physical inactivity), which can be acted upon with health promotion measures and preventive activities. Along with these unhealthy lifestyles there are other social determinants, such as living and working conditions, education or income level 4 .
The promotion of healthy lifestyles is essential to improve the health of the population and to prevent chronic diseases. And a key stage to internalize these behaviors is childhood and adolescence, which are critical periods of personal development 4 .
Hence the importance of collaboration between the health and social systems and the education system, to involve families and teachers in the design, implementation, monitoring and evaluation of health promotion actions in childhood and adolescence. This strategy must reach all age groups, including the elderly, who can benefit from specific actions to promote active and healthy aging 4 .
From the National Health System, the Chronicity Approach Strategy adds a key recommendation for the entire population: guaranteeing quality information on health promotion, prevention and treatment of chronic diseases, “fostering a culture of demedicalization of health and care ” 4 .
Along the same lines, scientific societies recommend encouraging the adoption of healthy lifestyles in medical practice in the face of patients’ misperception of a “drug that prevents and cures everything.” It also suggests promoting a critical spirit regarding the limits of medicine and technological advances 10 .
There are three levels of prevention according to the phase in which it is acted. The primary seeks to prevent the occurrence of the disease through actions against the risk factors that can cause it, related to the modification of lifestyles and environmental characteristics, especially in subjects who are especially exposed. The secondary school acts in the presymptomatic phase, when the pathology already exists even if the person who suffers from it does not know it because no noticeable symptoms have appeared and it has not been clinically diagnosed; It includes programs for the detection and early treatment of the disease. The tertiary focuses, once the disease is diagnosed, on delaying the progression of its chronic condition and preventing disability caused by it 4 .
The three levels are important, but primary prevention is the most decisive for reducing premature mortality in the future, since it focuses on the main risk factors for premature death: tobacco, hypertension, alcohol, high cholesterol and overweight 4 .
6. Need for partnerships between professionals, patients and institutions
The necessary comprehensive approach to the chronicity and sustainability of the health system in a context of increasing consumption of resources, making it more essential than ever the joint contribution of all the agents involved: professionals, health and social-health institutions, patients and their social-family environment.
On the axis is the family doctor, whose skills and continued relationship with chronic patients make him the professional with a better perspective of the population’s health problems. But the comprehensive and multidisciplinary approach to chronicity requires strengthening that central role with various alliances: between the different areas of care (1-2-day hospitalization in short-stay hospital units, to stabilize acute process decompensation or facilitate complementary tests), between formal health and social care providers (home help, patient school, expert patient), and with agents around the patient (family, friends and self-help groups) that provide informal support 10 .
It is about achieving a ‘great alliance’ between multiple health and social actors in which each and everyone has their role. The groups with which alliances could be established cover the entire spectrum of society: social services, patient associations, associations and community services (neighborhood associations, volunteering, industries), other administrations (town halls, councils and education), companies, media of communication, etc. 11
B) A NEW PATIENT MODEL: THE ACTIVE PATIENT
Until recently, the patient’s role was passive. But it is increasingly giving way to a new model that is based on the ‘active patient’. This patient is informed and trained in his illness, therefore has greater autonomy, is responsible for his health and his use of health and social resources is more responsible.
In addition, being an active patient or expert means that you comply better with treatments, lead an adequate lifestyle, have a better quality of life by feeling safe from your disease and decompensate less frequently. In that sense, investment in training actions for patients and caregivers is cost-effective 11 .
1. Information, essential for the chronic patient
The information is basic for the active patient. And even more so when he is chronically ill, he requires fluid communication with health and social-health professionals to develop his self-care over time. In this new leading role of the patient, the professionals who attend him are the most suitable to assess his training needs and his ability to assume them, although there may be other complementary methods such as the so-called ‘expert patients’ (who act as trainers of trainers) or the ‘patient schools’ (in which professionals train patients and caregivers) 11 .
At a time when ICTs allow citizens to directly exercise their right to information and communication, the so-called ‘Patient 2.0’, a patient trained and informed, with extensive experiences and skills and willing to share information and information Internet knowledge 11 .
In this context of increasingly accessible information, health authorities have an important function, the accreditation of web pages so that the patient citizen obtains truthful information 11 .
2. The need for self-care and autonomy of the chronic patient
In the chronic active patient, self-care are the practices that he performs for the maintenance of his own life, health and well-being. To be effective, support of the health system at all levels is essential. While traditional patient education offers information and technical knowledge, self-care education teaches skills to solve problems that may arise and achieve self-management of the disease itself. The purpose is that they achieve a self-management that is both self-effective, which entails a notable increase in the patient’s confidence in himself and his possibilities in facing his illness.
Clinical trials suggest that self-management teaching programs are more effective than patient education based solely on information 1 .
3. The family environment of the chronic patient
The family has become a fundamental support in chronic patient care, and its role is decisive in achieving curative or palliative goals. This active participation is even more noticeable in the care of the chronic home patient, since the integral approach of the patient includes family care as a unit 9 .
A key protagonist of home care is the primary caregiver, who is the person (family, close or hired) with better conditions to take care of the patient. Although the ideal is that there is an equitable distribution of this task among the whole family, the main caregiver should be the axis of care 9 .
In the context of the new active patient model, the primary caregiver and the family come to assume that role in the care of the chronic home patient. That is why it is very important that the training for families is oriented individually and is done in a flexible, progressive and practical way about basic aspects: food, hygiene, postural changes, cures, medication administration, control of certain symptoms, patterns of action before certain crises, or emotional support from other areas of friendship or associative 9 .
4. Patient schools
In the same key of self-care and active patient, the Strategy for the Approach to the Chronicity of the SNS recommends promoting initiatives and experiences of patient schools, active patient and expert patient programs, caregiver schools, professional caregiver networks and not professionals and other self-care support formulas 4 .
There are already many such experiences in Spain, such as those carried out from the “Patient Schools” of several autonomous communities; or from the University of Patients, which offers training in multiple areas: specialist patient, volunteer tutor, patient tutor and patient expert. In addition there are numerous self-help groups, in which the expert patient is an active health agent with an educational and facilitating role for groups of 10-15 patients who usually meet weekly until completing 6-10 sessions of an hour and a half to two hours and half. Its composition is variable (patients of a single pathology, or of several diseases with common needs), and also its teaching staff (one or two patients and different professionals as informative and clinical support). And with an important added value: they are a source of social and emotional support for the members of group 1 .
5. The role of patient associations
Similarly, patient associations play an essential role in strengthening identity as a group and offering social and emotional support. They share the day to day of the sick; its partners are informed, advised and advised; moments of help and awareness meeting are organized; contacts are maintained and social networks expand with other associations. In Spain there are more than 5,000 associations of chronic diseases. There are also volunteer organizations and others that provide services to the community 1 .
C) HEALTH CARE FOR CHRONIC PATIENTS IN SPAIN: SURVEY OF PATIENTS
The Z Hospital Barometer, which opened in 2014, is a survey on the quality of health care for chronic patients in Spain that makes the philosophy of the active patient a reality at birth from the associative movement itself.
Z Hospital is sponsored by 19 federations that bring together more than 1,000 associations and bring together 350,000 people with chronic disease or chronic symptoms. Chronic pathologies affect more than 19 million people in Spain, almost half of the population 13 .
The objective of the Barometer, which has published its second edition in 2015, is to evaluate the health care of chronic patients in Spain during the last 12 months, to shed light on the deficiencies of the NHS, to value its benefits and propose assistance improvements to health administrations 13 .
2. Most suffered chronic diseases
In the absence of surveys or reports on the exact number of chronic patients in Spain (it is estimated that 45% of the population over 16 suffer from at least one) and on the quality of health care they receive, the Z Hospital Barometer covers that empty and also analyzes some of the published figures on chronic diseases.
According to the 2013 SNS Report, the most frequent chronic health problems are low back pain; hypertension; osteoarthritis, arthritis or rheumatism; high cholesterol, and chronic cervical pain. In some cases there has been a significant increase in the last two decades: hypertension went from affecting 11.2% of the adult population to 18.5%; diabetes, from 4.1% to 7%, and high cholesterol, from 8.2% to 16.4%. In childhood, the prevalent chronic diseases are allergy (10%) and asthma (5.2%) 14 .
3. Profile of the chronic patient
According to data from the Chronos Report collected by Z Hospital, these pathologies affect more than 19 million people in Spain (almost 11 million women), and their prevalence is concentrated in people over 55 years of age and increases with age. They cause more than 300,000 deaths a year (74.45% of the total) and are the ones with the greatest impact on the hope and quality of life of citizens, especially the elderly. 14
Almost one in six adults aged 15 and over suffers from one of the following most frequent chronic disorders: low back pain (18.6%), high blood pressure (18.5%), osteoarthritis, arthritis or rheumatism (18.3 %), high cholesterol (16.4%) and chronic cervical pain (15.9%). Most of these problems are more frequent in women than in men 14 .
4. Satisfaction of the chronic patient with the functioning of the Health System
The II Barometer Z Hospital 2015 scores with 5.2 (out of 10) the attention received by Spanish chronic patients in the last year. That means that the quality of care in that area is still very improved for the second consecutive year, since the 2014 ‘note’ was 4.9 13 .
In the last year, satisfaction with the SNS decreased, which was lower for three out of 10 chronic patients, and higher only for one out of 10 13 .
Chronic patients place the greatest difficulty in accessing treatments in the different policies of the autonomous communities: 77% see this aspect “something or much worse” 13 .
For chronic patients there is no doubt that the SNS needs changes: 86% consider the healthcare model valid, but whenever it undertakes reforms to maintain the quality of care. While 46% believe that “some changes” are enough, 40% believe they must be “important” 13 .
Regarding the improvements that are considered priority, the list is the reduction of waiting times (57%), information on treatments (43%), equal access to care (42%) and access to treatments and specialists (38%) 13 .
The main demands for change in chronic patients are to reduce inequality between autonomous communities (43% consider this aspect “somewhat or much worse”), and improve access to rehabilitation treatments (42% believe that it has worsened) and most innovative therapies (29%) 13 .
Despite the demands for organizational changes, chronic patients greatly value the care received by general practitioners (80%) and specialists (79%) 13 .
5. Conclusions and recommendations
Among the recommendations of the Z Hospital Barometer 2015, there are six priority improvements in the care of chronic patients: reduce the waiting time to get an appointment, offer information about treatments, improve coordination among the specialists involved in the therapeutic process, reform and optimize the emergency care, remove barriers that hinder access to treatment and end regional differences in health care 13 .
And throughout the document, as the I Barometer 2014 already emphasized, there is a fundamental conclusion: the Strategy for the Approach to the Chronicity of the SNS approved in 2012 could be the basis of the change required by the healthcare system to get better patient care chronic, but needs to be launched and funds for its development 14 .
Ref 1. “Consensus document ‘Patient care with chronic diseases'”. Working Group of the Spanish Society of Internal Medicine and the Spanish Society of Family and Community Medicine, 2011.
Ref 2. “Health issues: Chronic diseases” . World Health Organization http://www.who.int/topics/chronic_diseases, accessed July 21, 2015.
Ref 3. “Acute versus chronic conditions”. MedlinePlus , accessed July 21, 2015.
Ref 4. “Strategy for the Approach to Chronicity in the National Health System” . Ministry of Health, Social Services and Equality, 2012.
Ref 5. “Attention Strategy for Patients with Chronic Diseases in the Community of Madrid” . Community of Madrid, 2013.
Ref. 6. “Strategy for health promotion and prevention in the SNS” . Ministry of Health, Social Services and Equality, 2014.
Ref 7. “Strategy for Chronic Patient Care in Castilla y León” . Junta de Castilla y León, 2013.
Ref. 8. “Patients with a diagnosis of heart failure in Primary Care: aging, comorbidity and polypharmacy . ” Magazine ‘Primary Care’ February 2011.
Ref 9. Vázquez Castro, J .; Ramírez Puerta, DN; Zarco Rodríguez JV: “Family environment and chronic patient” 2001.
Ref 10. “Chronicle Management Strategy. Consensus Document”. 2013.
Ref 11. “Chronic health problems: new orientations, new strategies”. Spanish Society of Family and Community Medicine, 2013.
Ref 12. Living Well with Chronic Illness: A Call for Public Health Action. National Academy of Sciences .
Ref 13. “Survey on the quality of health care for chronic patients in Spain. Complutense University of Madrid, 2015.
Ref 14. “Chronicity in figures”.