Self-care competence in the administration of insulin in older people aged 70 or over

ABSTRACT Objective: to analyze the self-care competence in the administration of insulin performed by older people aged 70 or over. Method: cross-sectional study carried out with 148 older people aged 70 or over, who performed self-administration of insulin. Data collection was carried out using a structured questionnaire and an adapted guide for the application of the Scale to Identify Self-Care Competence of Patients with Diabetes, at the participants’ home. Data analysis included descriptive and inferential statistical tests, with forward logistic regression. Results: the prevalence of self-care competence in the administration of insulin was 35.1%. Handwashing error was the most frequent in self-administration of insulin. Self-care competence was negatively associated with retirees and positively associated with senior patients who performed capillary blood glucose monitoring and skin pinching during insulin application. Conclusion: there was low self-care competence and it was associated with both the sociodemographic and the clinical characteristics with regard to self-application of insulin by the older people.


Introduction
Population aging and the influence of risk factors, such as obesity, sedentary lifestyle and inadequate food consumption, have contributed to the increase in the prevalence of chronic non-communicable diseases, especially Diabetes Mellitus (DM) (1) . In 2015, there were an estimated 415 million (8.8%) diabetic people worldwide, and people with this disease are expected to increase to 642 million in the next two decades (2) .
In line with the global trend, the prevalence of DM in the Brazilian scenario increased from 3.6% (95%CI: 3.3-3.8) in the 1990s to 6.1% (95%CI: 5.6-6.7) in 2015 (1) , increasing with aging (19.8% in individuals aged 65 years or over) (3) . This chronic condition was responsible for 62,466 deaths in the country and 1,015 wasted years, disability-adjusted life-years per 100,000 inhabitants (1) .
In the literature, it is observed that the geriatric population is more susceptible to micro and macrovascular complications due to a decrease in physiological reserve capacity, which leads to functional decline (4) . In addition, older adults aged 75 years or over are at an increased risk for death due to hyperglycemic events, as well as hospital readmissions due to hypoglycemic episodes, compared to younger age groups (5) .  (27.8-29.8%, p-value=0.391), and 15.7% also used oral antidiabetic agents (6) .
According to current guidelines in the country, insulin therapy is indicated for people with type 2 DM (DM2), when changes in lifestyle and use of metformin are not sufficient for glycemic control after one month of therapy. Insulin therapy is also indicated when glycosylated hemoglobin (HbA1c) values are above 8.5%, even after the use of the maximum dose of metformin and persistent symptoms of hyperglycemia, or when serum glucose levels are >300 milligrams per deciliter (mg/dL) (7) .
Self-administration of insulin requires from the user the mastery of the cognitive and psychomotor skills that constitute the learning of different procedures, including storage, transportation, preparation of the solution and application, as well as handling of syringes, needles or injection pens (7) . Therefore, proper use of insulin at home requires training, changes in daily life, discipline, availability for learning and dedication and interest to perform self-care. The types of insulin and its forms of use are varied and, depending on the number of daily applications and the effect of the dose and type of insulin used, the responsibility of the patient in the control of this chronic condition increases (8) .
The self-administration of insulin requires the individual to have competence for such activity.
Competence is the ability or capacity of an individual to perform certain activities, make decisions in the context of certain events, facts or circumstances. Self-care competence is the power of individuals to perform their own care in order to meet their particular needs. Such competence accompanies the development of individuals, beginning in childhood, reaching the highest degree of development in adulthood and decreasing in old age (9) .
Inaccuracies in the self-administration of insulin may adversely influence metabolic control, accelerate the progression of diabetes complications, and lead to discontinuation of treatment (10) . In addition, this situation is even more worrying among older people due to other factors added, such as visual deficit and cognitive and motor impairment, which make it difficult the self-administration of insulin and the Capillary Glycemia (CG) monitoring (11) .
The epidemiological aspects of DM have been extensively studied (1,12) , whereas there is a lack of information on self-administration of insulin, especially in older people. Previous studies at national level have identified frequent errors in the preparation and administration of insulin (10) , as well as improper disposal of residues generated by the administration of insulin at home (13) . This reality is not restricted only to Brazil, being also highlighted in studies at international level (14-16) . Therefore, in order to enhance the knowledge on the subject, the objective of this study was to analyze the self-care competence in the administration of insulin performed by older people aged 70 or over with DM.

Method
This cross-sectional study was carried out in the The older people who met the criteria mentioned above were considered as potential participants. Older people whose electronic medical records did not contain telephone contact information (n=283), telephone contact without success (n=213), change of address (n=25), death (n=46) and refusal to participate (n=82) were excluded from the sample. confidence interval (expressed as Z 2 α/2=1.96) and a maximum tolerable error (ε) of 0.05 (18) . The total sample consisted of 245 individuals.
A team composed of one nurse and four nursing students carried out data collection, in three stages. In the first stage, the team responsible for data collection was instructed to systematize data collection, in addition to enhance the knowledge about DM, insulin use and research methodology. A pilot study with five individuals was also carried out in order to determine the appropriate adjustments in the collection instruments, the estimated collection duration and other schedules.
In the second stage, a search for the names of older people, identified according to the HC, was performed in the Sisrede electronic medical record, in order to identify the Community Health Agents (CHA), the Family Health Teams, the telephone contact and the addresses of the older people. In this way, contact with the managers of the participating HC was made to explain the project.
Subsequently, telephone contact was made with each of the older people or their caregivers to identify those who performed self-administration of insulin and to schedule a home visit. All older people who performed self-administration of insulin were selected in order to schedule a home visit, in up to three attempts.
In the third stage, two data collection instruments were used: the questionnaire and the adapted guide for the application of the Scale to Identify Self-Care Competence of Patients with Diabetes (ECDAC) (19) . This scale was developed and validated by a nurse in 1982, at the Federal University of Santa Catarina (UFSC), based on the concept of self-care competence, according to the Dorothea Orem's theory (9) . In order to measure the reliability of the instrument, it was applied to 81 adults with DM, at their homes or at health institutions, and an alpha coefficient of 0.92 was obtained for the 27 items of the questionnaire (19) . contact and agreement to schedule the home visits by telephone, making it necessary to calculate the sample power. The significance level was set at 5% and the null hypothesized proportion was 27.54%. Maximum likelihood estimation was considered for the alternative hypothesis, that is, the estimate for the proportion found in the sample was 45.8%, resulting in a power of 0.99 (20)(21) .

Results
The profile of older people was characterized as a  Table 2. www.eerp.usp.br/rlae 5 Vianna MS, Silva PAB, Nascimento CV, Soares SM.

Discussion
In this study, an adequate self-care competence in the administration of insulin was identified among participants. The results revelead the mental limitation as the indicator that most affected the self-care competence.
Previous studies have shown that cognitive impairment increases the risk of nonadherence to diet, lack of glycemic monitoring, inadequate metabolic control, impaired quality of life (23) , severe hypoglycemia (24) , and difficulty performing complex self-care tasks, such as Preprandial blood glucose readings in adults should not exceed 130 mg/dL and the desirable HbA1c level is up to 7%. In older people, the tolerable HbA1c level is 8%, due to their greater vulnerability to hypoglycemic episodes and high risk of falls (7) . International recommendations suggest that, for functionally dependent older people, the target for HbA1c levels ranges from 7 to 8% and, specifically, for fragile older people or those with mental illness, these levels may reach up to 8.5% (25) .
Motor and visual limitations are additional aggravating factors, which may compromise the insulin self-application technique, making it difficult to handle the application device accurately and therefore have an impact on the metabolic control (10) . It should be noted that one in three participants had diabetic retinopathy, and vision impairment or loss of vision may affect the self-administration of insulin performed by older people, since it is necessary to visualize the syringe's graduation to ensure the right application dose and differentiate the types of insulin. It is important to note that the numbers indicating the graduation on the syringe are usually small, and sometimes with faint or blurred outlines, and the letters printed on the insulin vials indicating the insulin type and the expiration date are very small, which makes it difficult for older people to see.
In another respect, the high percentage of polypharmacy evidenced in this study is cause for concern, possibly due to the high burden of chronic diseases among  (26) . The therapeutic complexity associated with multiple comorbidities can lead to an inappropriate use of medications by older people, making self-care more complex, especially in cases where cognitive alterations are present. In addition, polypharmacy increases the chances of drug interactions and side effects, which can lead to intoxications, potentiation of drug effects and increased risk of falls (5) .
It is worth mentioning that almost all older people with diabetes also had SAH, which probably requires the concomitant use of antihypertensives.
Previous studies (27)(28) have demonstrated the influence of antihypertensive agents on glycemic control, pointing out the thiazide diuretics and beta-blockers as the pharmacological classes associated with insulin resistance and poor glycemic control.
Regarding the frequency of errors and successes in self-administration of insulin, handwashing was not performed by the majority of participants, a result that did not coincide with that of two other similar studies.
One of these studies, conducted by phone contact, found that only 3.9% of participants did not perform handwashing (29) , and the other study, carried out through a semi-structured interview, found that 11.2% performed handwashing sometimes or never (30) . The recommendation is to wash hands with soap and water before preparing insulin (31) .
Regarding air aspiration in the syringe and injection into the insulin vial prior to aspiration of the content, most participants did not perform this procedure, a result similar to that found in other studies (29)(30) . Air should be injected into the insulin vial in the amount corresponding to the dose to be drawn from the vial to prevent vacuum inside the vial (7) .
Regarding the disposal of sharps, approximately half of the older people discarded sharps in a hard flask and only half of them performed the procedure properly.
Similar results were found in a recent study conducted in the city of Fortaleza, CE, Brazil, which showed that 57.1% of the participants discarded in an inappropriate manner the waste generated by the administration of insulin in the ordinary household waste, even though they had been instructed on the appropriate manner to perform the disposal of this material (13) . International studies (32)(33) also found high percentages of inappropriate waste disposal resulting from insulin therapy, and the possible  One of the essential ways of making the person with DM aware of the importance of self-care is through the implementation of educational practices, and the participation of the nurse in these practices is fundamental.
To educate aiming at promoting self-care competence depends on the professional's technical competence, as well as the patient's willingness and interest (36) . The objective of this educational process is to provide strategies that promote behavior change, contributing to the improvement of the quality of life of the person with DM (37) .
Regarding the limitations of this study, the lack of references on the self-application of insulin specifically by the older people is highlighted, which made it difficult to develop the statistical calculations for the estimation of sample size and the calculation of the sample power.
Since this is a cross-sectional study, it was not possible to establish a cause and effect relationship between the variables.
Other limitations should be considered, such as difficulty in telephonic contact with the older people due to incorrect or missing telephone numbers, lack of financial resources and short deadlines that did not allow search for the addresses without a prior telephone contact.

Conclusion
Based on the results of this study, it was identified that handwashing, air aspiration in the syringe and injection in the insulin vial and disposal of sharps in a hard flask are the main errors in the self-application of insulin.
Only the mental limitation showed a strong correlation with self-care competence. Retirement, performance of CG monitoring and skin pinching for insulin application were associated with the outcome variable.
In view of these results, it is considered essential the interdisciplinary care to the older person with DM through a special and individualized care, which must be provided to this population. In addition, identifying and analyzing errors and difficulties related to the selfcare competence in the administration of insulin in older people aged 70 or over with DM, enables professionals to contribute in their area of knowledge and stimulate a comprehensive care focused on older people.