Prevalence and intensity of chronic pain and self-perceived health among elderly people: a population-based study

OBJECTIVE: to identify the prevalence and intensity of chronic pain among elderly people of the community and to analyze associations with the self-perceived health status. METHOD: cross-sectional study with a populational sample (n=934), conducted through household interviews in the city of Goiânia, Brazil. The intensity of chronic pain (existing for 6 months or more) was measured using a numerical scale (0-10) and the self-perceived health through a verbal scale (very good, good, fair, poor, very poor). For the statistical analysis, the absolute frequency and percentage, CI (95%), Chi-square test, Odds ratio, and regression analysis were used. Significance of 5%. RESULTS: The prevalence of chronic pain was 52.8% [CI (95%):49.4-56.1]; most frequently located in the lower limbs (34.5%) and lumbar region (29.5%); with high or the worst possible intensity for 54.6% of the elderly people. The occurrence of chronic pain was associated with (p<0.0001) a worse self-perception of health (OR=4.2:2.5-7.0), a greater number of chronic diseases (OR=1.8:1.2-2.7), joint disease (OR=3.5:2.4-5.1) and the female gender (OR=2.3:1.7-3.0). A lower intensity of chronic pain was associated with a better self-perception of health (p<0.0001). CONCLUSION: the majority of the elderly people of the community reported chronic pain, of a severe intensity, and located in areas related to movement activities, thus influencing the morbidity and mortality of this population.

living in the urban zone of the city of Goiânia consisted of 934 individuals.
The concept of living at home was "sleeping in the residence for more than four days per week". Those who lived at home, however, were not found after three attempted visits by the observer were excluded, as were those who achieved scores <13 in the evaluation of cognitive ability through the Mini Mental State Examination (MMSE) (13) , which provided a total of 872 elderly people.
The geographical area of the study was defined For each CS, the first block was selected and, within this, a corner where the data collection was initiated.
From the selected corner, the first residence was visited, excluding any property that was not residential. For each SC selected, and from the block defined, the households were visited until 17 elderly people had been interviewed.
Data were collected from the elderly people in their homes by properly trained people. After identification by the interviewer, the elderly people were informed about the study aims, research methods, risks/benefits, guarantee of anonymity and confidentiality of the data.
The elderly people who met the inclusion criteria were invited to participate and those who agreed were given two copies of the Terms of Free Prior Informed Consent.
Next, the questionnaire, composed of 12 sections (identification, social profile, caregiver, general health and family history, with a arterial pressure check and The outcome variable for this study was chronic pain (existing for six months or more (14) ). Measured from the main pain, i.e., the one that most bothered the elderly person, felt in the seven days preceding the interview. To measure the intensity, a numerical range (0-10) was used, in which zero=no pain; 1,2,3 and 4=mild pain; 5 and 6=moderate pain; 7,8 and 9=severe pain and 10=worst possible pain. Exposure variables: self-perceived health status (evaluated using a verbal rating scale ("very good", "good", "fair", "poor", "very poor"; gender (male/female) and age by age group
In the women, the chance of evaluating the health as "fair" was 2.6 times higher compared with the evaluation "very good or good" (OR=2,6;1.7-3.8); and nearly six times higher compared to the evaluation of "poor and very poor" health (OR=5.9;2.9-12.0). In the men, these chances were lower (OR=1.5;0.9-2.5 for "fair" and 1.6;0.6-3.9 for "poor and very poor").
In Table 4, it can be observed that self-perceived health was associated with a greater intensity of chronic pain (χ 2 =72.9; p<0.0001).
Also related to the intensity of chronic pain and self-perceived health, the regression analysis ( Figure 1) showed that, according to the numerical scale (0-10), when the pain scores were lower, indicating less severe pain, the elderly people evaluated themselves as having better health.  Rev. Latino-Am. Enfermagem 2014 July-Aug.;22(4):662-9.

Discussion
Studies (4)(5)(6)(7)(8)(9)15) have shown that the prevalence of chronic pain can range from 29.7% to 89.9%. This variation may result from the influence of factors that include the definition of the time established for the pain to be classification as chronic, regional sociodemographic differences, the methodology used for data collection and variations among the data collection instruments used (16) .
Given the extent of the chronic pain problem, the findings of the present study corroborate those of national and international studies, indicating a high proportion of pain complaints among the elderly people of the community, which may mean prolonged suffering, which is sometimes ignored and under-treated.
Cross-sectional studies (4)(5) , performed in Brazil with populational samples, conducted through household interviews and temporal characterization of the chronic pain as existing for six months or more, showed a similar prevalence of chronic pain (51.7%) to the present study among 451 elderly people of Londrina, PR, and a lower prevalence (29.7%) among 1,271 elderly people of the city of São Paulo, SP. Accordingly, the need is highlighted for further research with representative samples of the elderly population, in other regions of Brazil, with a view to identifying the extent of chronic pain prevalence in this age group and regional factors that may protect or expose the elderly people to the persistent painful experience. The greater representativity for the women corroborates the findings of studies conducted with the elderly population (4,(15)(16) , indicating the feminization of old age.
The intensity of the chronic pain was high (severe and worst possible pain for 54.6% of the elderly people), as also shown in other studies (4,(15)(16) , in which the proportions of severe pain reached over 50.0%. In Spain (17) , the prevalence of moderate to sever intensity pain was 86.4%; In Brazil (4) , this reached 45.8% for moderate pain and 46.0% for severe and very associated with a poorer self-perception of health. In Finland (23) , a study presented a strong association between self-perceived health and chronic pain, regardless of chronic diseases, gender or age.
There was a significant association between selfperceived health and chronic pain among the women of this study, however, not among the men. A study indicated that men give a worse evaluation of their health when they are at greater risk of being affected by a fatal event (24) . It is assumed that, due to the life expectancy of women being higher than that of men, they have an increased chance of developing chronic and degenerative diseases and pain and therefore evaluate their health more negatively, due to associating it with losses in the quality of life.
In Canada, prolonged high intensity pain was associated with worse self-perceived health (11) , as in the present study. In Finland (23) , the prevalence of fair health was 38.1% among those who reported pain once a week (for 46.0% the pain was daily or continuous), and the prevalence of poor health was 5.1% among those who reported pain once a week (for 31.7% the pain was daily or continuous). The proportions increased with the higher frequency of reports of more intense pain.
To achieve pain control is a right of the general population and also the elderly person (4,11,21) . The constant pain complaints, associated with a worse selfperception of health, highlight the need for longitudinal studies that investigate the influence of persistent pain on mortality and morbidity in elderly people. In this sense, it is essential that chronic pain is routinely evaluated and measured in the healthcare services and that the entire team is trained to intervene or to refer people for specialist treatment (25) . For this, health professionals should receive adequate training, from the undergraduate course, to conduct an evaluation of the occurrence of pain in the general population, across the life cycle, and within their competences, so that they prepared to intervene, using the diversity of approaches available to work in an interdisciplinary manner.
A limitation of the study was being part of a larger study, in which several outcomes were investigated and not specifically chronic pain, which did not allow painful experience. A further limitation of the study is that only elderly individuals with MMSE scores >13, and who were able to hear and speak were evaluated, which excluded individuals with severe dementia, severe deafness and language deficits, limiting the generalizability of the results to this populational group.

Conclusion
The majority (52.7%) of the elderly people suffered chronic pain, of high intensity (54.6%), in locations