This study aimed to assess the association between individual and contextual factors of CKD patients and limitations in ADL in the Brazilian population. Almost half of the Brazilian population with CKD has limitations in terms of daily living habits, directly or indirectly related to biopsychosocial factors. Less limitations in ADL were mainly related to factors such as a good/average health perception, living in urban areas, and having access to private health insurance. On the other hand, presenting some type of physical or intellectual disability, continuous drug use, and undergoing hemodialysis were factors related to greater limitations in ADL.
Factors such as the individual's color, age, sex and paid work were not associated with inequality due to the limitations in ADL, even though the predominance of CKD diagnosis in the population was from 30 to 50 years. Low education level implied a higher limitation in ADL because of their interference with the behavior and health of individuals. People with greater educational vulnerabilities were more economically vulnerable as soon as they were more sedentary, obese, alcoholic and smokers, with a higher prevalence of NCDs, such as CKD (TONELLI; RIELLA, 2014). These diseases are added to the social inequalities that befall this population group and, in the nonwhite population, which affect the conditions and use of healthcare services, complicating the insertion in health education programs and other public prevention policies (MALTA; MOURA; BERNAL, 2015).
Another sociodemographic variable that was directly related to limitations in ADL in individuals with CKD was the area of residence. The population that lived in urban areas presented fewer limitations than that in rural areas. This occurs because the inhabitants of rural areas possess different values due to their formation based on the symbolism of the land and intimately associate their health with the ability to perform fieldwork, and while this is not affected by diseases, they feel healthy. This fact decreases the perception of chronic diseases and generates a lower demand for healthcare services. Lower access to healthcare facilities is another important factor since these facilities are concentrated in urban areas, demanding locomotion and availability from these individuals. Thus, it is necessary local and regional public policies toward the population in rural areas, aiming at providing equitable care and the possibility of early diagnosis (ARRUDA; MAIA; ALVES, 2018).
Interestingly, it was shown that patients who used continuous drug use presented greater daily living limitations than those who did not. It is necessary to be careful with the interpretation of this inference since it does not mean that drugs worsen functionality but rather that CKD is an insidious and minimally symptomatic disease, favoring nonadherence to therapy, which only occurs when the disease becomes more severe. Furthermore, insufficient information for patients can corroborate nonadherence to therapy, especially in the early stages of the disease (SGNAOLIN; FIGUEIREDO, 2012). It can be inferred that individuals who use these drugs are often in later stages of the disease and possess more limitations. It is worth noting that the nonuse of drugs due to nonadherence to therapy can be an aggravating factor for the disease (ALMEIDA et al., 2019).
It was also verified that hemodialysis corroborated greater daily living limitations. Hemodialysis is associated with several physical consequences, such as arterial hypotension, vomiting, dizziness, cramps, headache, and fainting (TERRA et al., 2010). This procedure decreases the quality of life and causes personal, familiar, and social repercussions. CKD impacts the routine of daily activities, such as diet, traveling, feeding, work, and social life, in addition to generating dependence in these individuals to perform dialysis sessions (JESUS et al., 2019).
Even with such complications, hemodialysis is still one of the safest and most effective procedures to replace renal function and promote a greater quality of life for individuals with CKD. On the other hand, peritoneal dialysis increases without bringing individual and social restrictions, since it can be performed inside the patient's home, the ability to cause fewer changes in the daily routine and an alternative encouraged by specific policies to improve patients' lives (MORAES et al., 2018). Most likely, the greater social care for contextual adequations and the emphasis on the education of patients in RRT can better explain the decision making between hemodialysis and peritoneal dialysis (XUE et al., 2019). Furthermore, peritoneal dialysis is a more cost-effective procedure for the healthcare system (WANG et al., 2018; GHANI; RYDELL; JARL, 2019).
Other important aspects approach the perception of depressive symptoms, observed in more than half of CKD patients. CKD requires specific treatment and demands adaptation and changes in lifestyle, which can make individuals more likely to present anxiety and depression symptoms. Furthermore, these demanded changes can result in social isolation and loss of functional, physical, or mental performance, which may directly limit the life of these individuals (PRELJEVIC et al., 2013).
Health self-perception is also a useful indicator to evaluate individual health and synthesize its physical, mental, and social dimensions (SAEZ; VIDIELLA-MARTIN; CASASNOVAS, 2019). Furthermore, it can indicate the effectiveness of health education, which provides society with better health situations and life habits. The adjusted analysis of the results showed an inversely proportional relationship, in which the better the health perception by the individual is, the lower his limitations in daily living. The tracking of health perception seems to be a useful instrument in health services to identify individuals prone to clinical and functional decline and risk of death (INUZUKA et al., 2018).
Individuals with private health insurance were able to minimize the limitations in the daily living of people with CKD. Having private health insurance may be related to social status and greater access to favorable living conditions, as well as to healthcare services. The supplementary system can increase the flexibility and rate of examinations and procedures, often providing greater convenience and ease for individuals able to pay for it, therefore reflecting the reduction of complications and limitations caused by this disease (ZIROLDO; GIMENES; CASTELO JUNIOR, 2013).
Analysis of smoking habit variables revealed an intriguing scenario according to the adjusted analysis: people who smoked presented fewer daily living limitations than those who did not currently smoke. People with CKD who still smoke are probably in the early stages of CKD or still do not suffer great consequences from smoking (ELIHIMAS JUNIOR et al., 2014). It is also inferred that those people who do not smoke may have abandoned this habit for already being in more severe stages of CKD and presenting an impaired health status. Based on this, it is important to establish early educational and assistance actions to stimulate the reduction of tobacco products to delay the limitations caused by this habit.
Furthermore, it was revealed that individuals with CKD face greater daily living limitations when also presenting some degree of physical disability. These limitations, when associated, can extend beyond the habits and routine of these people and interfere, for example, with transportation to health facilities, therapeutic interventions, and emotional health (RAMÍREZ-PERDOMO; SOLANO-RUÍZ, 2018).
Finally, it is worth noting that among the limitations verified in the study, the transversality of the study is highlighted for preventing the establishment of cause-effect relationships between variables, as well as the fact that the outcome was evaluated through self-reports and not by the official record of the medical diagnosis, although it is described that several morbidities present good sensitivity to self-reports.