1. Background
Pain is a common complaint of the elderly. As the number of individuals older than 65 years continues to rise, frailty and chronic diseases associated with pain would likely increase (1). Therefore, primary care physicians would face a significant challenge in pain management in older adults. The elderly are more likely to have arthritis, bone and joint disorders, cancer, as well as other chronic disorders associated with pain (2). Pain is the important problem between 25% and 50% of community-dwelling elderly (3). Prevalence of pain in geriatric nursing home residents is even higher, which is estimated to be between 45% and 80% (4). The elderly are often untreated or undertreated for pain. Barriers for effective management include challenges to proper assessment of pain, underreporting by patients, atypical manifestations of pain in the elderly, misconceptions about tolerance, and addiction to opioids in elderly (1). Consequences of under treatment for pain in the elderly population are depression, anxiety, social isolation, cognitive impairment, immobility, sleep disturbances, and losses in the quality of life (5, 6). Pain plays a key role in the mental health of older adults (7). Reasons that physicians usually indicate inadequate pain control might include lack of training, inappropriate pain assessment, and reluctance to prescribe opioids (3). As is the case in many developing countries, the elderly population in Iran is significantly growing and is predicted to have more than 26 million seniors (over 60 years old) in Iran by 2050 (8). The elderly (65 years and older) represent more than 7% of Irans’ population now (9) and is estimated to be more than 10% and 21% in 2025 and 2050, respectively (10, 11). For convenient management of pain in elderly patients, it is necessary to use appropriate pain assessment methods. There are different self-report scales for pain evaluation in elderly individuals, among them FPS-R (faces pain scale-revised) and NRS (numerical rating scale) are 2 useful pain assessment tools. Both these scales score the sensation of pain on a widely accepted 0-to-10 metric, which the FPS-R is accompanied with different sad to happy faces according to level of pain in a person.
FPS-R is widely used for pain assessment in children, however, due to simplicity of implementation, this instrument is frequently used for pain assessment in older adults in clinical practices as well.
Despite the widespread use of these scales for pain measurements in geriatrics, only a few studies have compared them. Considering the above facts, this study was conducted to compare 2 scales: FPS-R and NRS in the bed-ridden elderly population of Hamadan, Iran.
2. Methods
In this cross-sectional study, all 120 elder bed-ridden patients, who were older than 65 years, were studied during 3 months (May-July 2016) by using a convenient sampling. Patients were selected from the internal wards of Shahid Beheshti hospital, which is the referral center for internal medical disorders in Hamadan. For measuring pain frequency and intensity in each patient, we used FPS-R (faces pain scale-revised) and NRS (numerical rating scale) as self-report scales.
Although both these measures are scored from 0 to 10 (0 indicating no pain and 10 is the worst experienced pain), NRS contains both even and odd numbers and FPS-R has only even numbers as a scoring scale.
We used trained nurses for patient interviews. Questions such as how much pain did they have at the moment and if they had any pain, how long did it take to feel better were asked. Nurses also helped them express their pain intensity by choosing the right number (NRS) or the right picture (FSP-R), which indicated the best for their pain condition according to the above scales. The inclusion criteria for this study included being over 65 years as well as getting verbal consent. Severely ill patients and those who could not estimate their pain intensity for different reasons (like severe dementia) were excluded from the study. We defined persistent pain as pain that lasts for a prolonged period (usually more than 3 - 6 months (12). All participants' information were gathered in a checklist and then analyzed using SPSS software (version 16.0, SPSS, Chicago, IL). Normality was evaluated by Kolmogorov-Smirnov. ANOVA, Chi-square, t-test, and Pearson correlation was used to evaluate the relationship between the 2 scale's correlations. The Ethics Committee of Hamedan University of Medical Sciences approved the ethical considerations of the present study under No Ref:p.16.35.320.
3. Results
Totally, 120 patients older than 65 years entered the study. The most frequent diagnoses in these patients were hypertension (55%), COPD (Chronic Obstructive Pulmonary Disease) (20%), malignant neoplasms (10%), and diabetes mellitus (7.5%). In total, 78 (65%) participants were male and 42 (35%) were female. Mean ± (SD) age was 74.9 ± (6.8), which did not have significant difference in men and women (74.98 ± (6.8) in men and 75 ± (6.9) in women, respectively. All patients (100%) had some degree of pain, which started from 1 month to more than 6 months ago. Among them, 115 (96%) had a persistent pain that started more than 3 months ago. Pain frequency and intensity in the study population, according to FPS-R and NRS scales, is shown in Table 1. There was a strong correlation between the 2 scales using Pearson correlation method (r = 0.735, P < 0.001). Analysis of pain intensity in terms of gender did not show any statistically significant difference between men and women (Table 2). The age group analysis in participants showed a higher pain intensity in the 75 - 85 year old group compared to other age groups with both FPS-R and NRS scales, which was statistically significant (Table 2).
Table 1.Pain Frequency and Intensity in the Study Population Based on NRS and FPS-R Scalesa
| Level of Painb | NRS | FPS-R | ||||
|---|---|---|---|---|---|---|
| N | % | N Cumulative | N | % | N Cumulative | |
| 3 | 3 | 2.5 | 2.5 | |||
| 4 | 11 | 9.2 | 11.7 | 24 | 20 | 20 |
| 5 (Moderate pain) | 21 | 17.5 | 29.2 | |||
| 6 | 24 | 20 | 49.2 | 45 | 37.5 | 57.5 |
| 7 | 13 | 10.8 | 60 | |||
| 8 | 25 | 20.8 | 80.8 | 36 | 30 | 87.5 |
| 9 | 18 | 15 | 95.8 | |||
| 10 (Worst pain) | 5 | 4.2 | 100 | 15 | 12.5 | 100 |
| Mean pain intensity (± SD) | 6.5 (± 1.8) | 6.7 (± 1.88) | ||||
| Total | 120 | 100 | 120 | 100 | ||
aNo items were found at level 0, 1, 2 so these levels were not listed in this table.
bNRS contains both even and odds numbers, but FPS-R has only even numbers.
Table 2.Comparison of Mean Pain Intensity in Different Sex Groups and Different Age Groups of the Participantsa
| Variable | FPS-R | NRS | |
|---|---|---|---|
| Sex | Male | 6.53 ± 1.84 | 6.56 ± 1.81 |
| Female | 7.00 ± 1.93 | 6.97 ± 1.77 | |
| P value | 0.20 | 0.23 | |
| Age, yb | 65 - 74 a | 6.44 ± 1.55 | 6.62 ± 1.78 |
| 75 - 84 b | 7.00 ± 1.65 c | 7.07 ± 1.79 c | |
| ≥ 85 c | 5.44 ± 1.02 | 5.36 ± 1.28 | |
| P value | 0.04 | 0.014 |
aValues are expressed as mean ± SD.
bIn post hoc analysis (tukey) significant difference was between b*c (FPS-R: P = 0.04, NRS: P = 0.014).
Post hoc analysis indicated that 2 age groups (75 - 85-year-old and > 85-year-old) had statistically significant different pain intensities (Table 2).
4. Discussion
Pain is a common problem in the elderly population and our results showed that all of the hospitalized, bed-ridden patients in Hamadan, had pain problems. Furthermore, pain intensity in most participants was higher than the median (score 5 or higher according to table 1), which is higher than other studies. Results of a study done on elderly hospitalized patients, in Italy, which applied NRS, showed that pain the prevalence was 63% in the study population (13). Most of the elderly population in our study (96%) had a persistent pain that started more than 3 months ago. Results of 2 different studies showed persistent (i.e. chronic) pain affecting more than 50% of older individuals living in a community setting and more than 80% of nursing home residents (14, 15). Results of another study in Tehran, Iran indicated that 72.8% of the elderly residents in 2 private nursing homes reported some degree of pain at the time of study and 66.7% reported persistent pain (5). In addition, in a cross-sectional study in Japan, the prevalence of pain among 9 healthcare facilities was 47.2% and between self reported pain reasons, mental health issues had the greatest portion (OR: 9.18, 95%CI 1.27 - 66.52) (16). Measuring pain intensity using the FPS-R scale showed that most participants (80%) had moderate to severe pain, which means they assigned the score of 6 or more to their pain severity. Results of a study on elderly adults, from 6 nursing homes in Hong Kong, that used a geriatric pain assessment scale, showed a pain intensity of 4.51 on a 10-point scale, which was lower than our results (17). A recent study of elderly people that resided in the community setting in Brazil showed that 52.8% of the elderly population suffered from chronic pain; among them 54.6% reported highest or the worst possible pain intensity (18).
In our study, the pain intensity measured by the NRS scale showed similar results, therefore, 106 (88.3%) patients rated a pain intensity of 5 or more (moderate to worst pain). These self-rating pain scales are suitable for measuring pain in the elderly. In different studies, their effectiveness in assessment of pain intensity in the elderly has been proved (19-21). Results of present study showed a strong correlation (r = 0.735, P < 0.001) between the 2 scales using the Pearson correlation method, which is very similar to results of the Kim EJ et al. study in Korea. Like our study, they showed a strong correlation (r = .73, P < .001) between the FPS and the NRS in older adults in Korea (21).
In another study, validity and reliability of these scales have been shown in traditional and electrical usages (22). Comparing pain intensity in women and men did not show a significant difference and the results were the same with FPS-R and NRS scales. However, other studies indicated that the pain intensity in women was higher than men (23, 24). In a study done in California, older women, with a low income, who were insufficiently active during their leisure time, had higher prevalence of chronic pain (25). In some investigations, the role of ethnicity in pain intensity is being considered in older adults (this can be a new subject in pain topics) (26).
Finally, analyzing pain intensity in different age groups using ANOVA showed that pain intensity was highest in the 75 - 85 year old age group and the lowest in the individuals who were older than 85 years. Most clinical studies suggest a relative decrease in intensity of pain symptoms associated with different disorders in adults of advanced age (27).
4.1. Conclusions
Pain has a remarkable prevalence in bed-ridden patients in Hamadan, Iran; therefore, it is necessary to evaluate each elderly hospitalized patient regarding pain using appropriate pain assessment methods. Two different scales used in this study (FPS-R and NRS) showed a strong correlation to assess pain in the study population, among them, FPS-R seems to be more convenient to administer, especially in cognitive disorders, and requires no equipment except for the photocopied faces. Evaluating pain intensity in the study population showed that most participants had moderate to severe pain, which emphasizes the necessity for appropriate treatment in the geriatric population.
