1. Background
Anemia is a significant health problem worldwide in all age groups. According to the World Health Organization (WHO), 24.8% of the world's population is affected by anemia (1). The prevalence of anemia increases with age, especially at the beginning of aging; however, it accelerates from 80 years (2-4). Elderly population is growing worldwide, especially in the developing countries such as Iran, which are not yet ready for the challenges of this population increase (5). WHO defines the index of anemia as hemoglobin (Hb) less than 13 g/dL in males and less than 12 g/dL in females (6, 7). Anemia is more common in females and according to WHO, its global prevalence is 21% - 80% in them (8). Generally, the prevalence of anemia in community-dwelling elderly is 12%, in hospitalized ones is 40%, and in nursing home residents (NHR) is 47% (9).
In general, age-related physiological changes, reduced food intake, multiple underlying diseases, and inadequate nutritional care are among the main causes of anemia in the elderly (10). According to WHO, 40% - 89% of female cases diagnosed with anemia are associated with the iron deficiency, and according to studies, 40% of anemic cases are female elderlies living in nursing homes (11), which inadequate iron intake and/or chronic loss of iron due to gastrointestinal bleeding are the main causes of this complication. In general, among nursing home residents, iron deficiency anemia (IDA) is more related to the loss of blood than lack of nutrients (6, 12).
Although anemia is not a disease, it is a symptom of underlying illness that can affect cardiovascular function, physical activity, mobility and movement, risk of falling, hospitalization, disability, and mortality. In addition, it increases the risk of frailty syndrom, depression, delirium, and cognitive impairment, and affects the quality of life in the elderly (11, 13-21). In other words, the probability of hospitalization in older patients with anemia living in nursing homes is twice more than that of their peers without this complication (6).
In older adults, anemia is asymptomatic and usually occurs in the early stage of a disease (6). Compared to youth, fatigue and other common symptoms of anemia are less common in the elderly; therefore, the onset of anemia in the elderly is hidden and their complaints of anemia are often ignored (22). Despite the high prevalence of anemia in the elderly, this complication often remains undiagnosed and untreated (23).
Due to the high prevalence of anemia in the older adults, its association with underlying diseases, and its direct impact on the health of individuals, this complication is an area of interest in clinical research (24). Regarding the high prevalence of anemia in nursing home residents, the International Association of Gerontology and Geriatrics emphasizes the need for research on the prevalence of this condition and its early diagnosis and treatment in the elderly living in such places (25).
The prevalence of anemia is reported based on the impact of climatic, social, economic, and cultural conditions in the region (26). In Iran, only a few studies are conducted on the prevalence of this conplication in certain groups such as those with cardiovascular and chronic kidney diseases (27). Considering the lack of epidemiological studies on anemia in older adults, and that so far no studies in Iran compared the prevalence of anemia among the elderly living in nursing homes and community, the current study is of higher significance. The results of these studies can be used in order to better plan for diagnosis and treatment of this condition.
2. Objectives
The present study aimed at comparing the prevalence of IDA among elderly females living in nursing homes and community in Iran and its effective factors.
3. Methods
3.1. Design and Participants
The current cross sectional study was conducted on elderly females living in nursing homes and community in Bushehr Province, Iran from July to November 2017. The inclusion criteria of the study were: age over 60, female gender, having a file in the Welfare Organization of Bushehr, signing informed consent to participate in the study, and lack of iron supplementation, and for seniors living in nursing homes, other criteria were at least one year of residency in the nursing home and absence of anemia at the study onset. Bushehr Province is located in Southwest of Iran. There are two nursing homes, in Bushehr and Borazjan cities. In the current study, all elderly females living in nursing homes of Bushehr Province were selected by a complete sampling method. The total population of the elderly females living in the two nursing homes supervised by the Welfare Organization was 180; after the application of the exclusion criteria, 41 subjects remained and the sample size was 324.
The sample size was determined according to the study by Alizadehasl et al. (27). It should be noted that the two groups were matched by social class. In the study, a demographic information form including age, duration of living in the nursing home, marital status, and the number of children was used.
After obtaining the necessary permissions from the Ethics Committee of Bushehr University of Medical Sciences (ethics code: b-93-16-2) and the Welfare Organization of Bushehr Province, and getting informed consent from the elderly or their legal guardians, 5 mL clot and 1.5 mL oxalate samples were taken from each subject by a specialist and after observation of the cold cycle were transferred to Sina Lab in Bushehr city to measure serum ferritin, hemoglobin, and C-reactive protein (CRP) levels. Ferritin level of samples was measured by ELISA (the enzyme-linked immunosorbent assay) technique using a MAN kit, and hemoglobin by Sysmex K1000. Since in case of the positivity of CRP, ferritin is overestimated, all elderly patients with positive CRP were excluded. Based on the WHO diagnostic criteria, hemoglobin values less than 12 g/dL were considered as anemia (7). Anemia classification based on hemoglobin level consists of less than 8 g/dL as severe, 8 - 10 g/dL as moderate, and greater than 10 g/dL as mild (28).
3.2. Statistical Analysis
The prevalence of anemia was estimated according to place of residence (nursing home vs. community). The data were analyzed by SPSS version 21 (IBM, New York, USA) software using descriptive statistics (mean and standard deviation). In order to investigate the normality of data distribution, the Kolmogorov-Smirnov test was used. In the current study, the significance level was less than 0.05. To compare anemic and normal individuals, the simple logistic regression was used and after adaptation to the marital status and age, the adapted OR was obtained. Also, in order to compare older adults living in nursing
homes and community and the independent variables affecting them, the simple logistic regression was used and ORs, CIs associated with their use, and their significance levels were achieved.
4. Results
A total of 365 elderly females participated in the study, among which 41 (11.2%) were nursing home residents. The mean ± SD age of participants was 82.00 ± 5.79 years and 8% were single. The mean hemoglobin and ferritin levels in the participants were 12.6 ± 1.04 g/dL and 15.00 ± 5.11 µg/dL, respectively. Demographic data of the older adults are shown in Table 1.
Table 1.Characteristics of the Elderly Participants in Busheher Province in Terms of Anemiaa
| Without Anemia (N = 258) | Mild Anemia (N = 84) | Moderate Anemia (N = 22) | With Anemia (N = 106)b | Crude Model | Adjusted Modelc | |||
|---|---|---|---|---|---|---|---|---|
| OR (95% CI) | P Valued | OR (95% CI) | P Valued | |||||
| Age, y | 81.51 ± 5.87 | 83.61 ± 5.29 | 84.00 ±5.47 | 5.30 ± 83.69 | 1.07 (1.02 - 1.11) | 0.001 | 1.07 (1.02 - 1.11) | 0.001 |
| Hemoglobin level, g/dL | 13.02 ± 0.66 | 11.55 ± 0.23 | 10.14 ± 0.58 | 0.66 ± 11.26 | - | - | - | - |
| Number of children | 5.90 ± 2.38 | 5.88 ± 2.24 | 6.09 ± 2.20 | 2.22 ± 5.92 | 1.00 (0.91 - 1.10) | 0.936 | 0.97 (0.85 - 1.11) | 0.675 |
| Number of female children | 3.32 ± 1.58 | 3.20 ± 1.50 | 3.09 ± 1.54 | 1.50 ± 3.17 | 0.94 (0.81 - 1.09) | 0.429 | 0.87 (0.73 - 1.04) | 0.874 |
| Number of male children | 2.61 ± 1.28 | 2.67± 1.31 | 3.13 ± 1.12 | 1.28 ± 2.77 | 0.29 (0.92 - 1.31) | 0.290 | 1.10 (0.89 - 1.36) | 0.352 |
| Nursing home residency | 1.65 (0.84 - 3.24) | 0.141 | 1.93 (0.96 - 3.87) | 0.065 | ||||
| No | 233 (90.3) | 75 (89.3) | 15 (68.2) | 90 (84.9) | ||||
| Yes | 25 (9.7) | 9 (10.7) | 7 (31.8) | 16 (15.1) | ||||
| Marital status | 0.84 (0.34 - 2.05) | 0.704 | 1.04 (0.41 - 2.60) | 0.927 | ||||
| Married | 238 (92.2) | 79 (94.0) | 20 (90.0) | 99 (93.4) | ||||
| Single | 20 (7.8) | 5 (6.0) | 2 (9.1) | 7 (6.6) | ||||
| Duration of nursing home residency, y | 1.37 (0.99 - 1.90) | 0.054 | 1.51 (1.07 - 2.13) | 0.016 | ||||
| No | 233 (90.3) | 75 (89.3) | 15 (68.2) | 90 (84.9) | ||||
| 1 | 6 (2.3) | 2 (2.4) | 1(4.5) | 3 (2.8) | ||||
| 2 | 18 (7.0) | 6 (7.1) | 3 (13.6) | 9 (8.5) | ||||
| 3 | 1 (0.4) | 1 (1.2) | 2 (9.1) | 3 (2.8) | ||||
| 4 | - | - | 1 (4.5) | 1 (0.9) | ||||
Abbreviations: CI, confidence interval; OR, odds ratio; SD, standard deviation.
aValues are expressed as mean ± SD or No. (%).
bAdjusted based on age and marital status
cNumber of patients without anemia was the baseline for comparison.
dP < 0.05 was considered significant.
Based on the amount of ferritin, more than half of the participants had anemia, but based on hemoglobin level, 30% of them had anemia, while only 6.01% had moderate anemia; therefore, the overall prevalence of IDA in the community-dwelling older adults (CDOA) and nursing home residents was 39% and 27%, respectively.
More than 68% of older adults lived in the nursing homes for less than two years. The crude and adapted ORs indicated that living in nursing homes was a risk factor for anemia (OR = 8.69, 95% CI = 3.28 - 23.03) (Table 1).
According to Table 2, the age of the participants living in nursing homes was significantly less than that of the community-dwelling subjects (OR = 0.94, 95% CI = 0.89 - 0.99). On the other hand, with the increase in age, the risk of anemia increases; therefore, according to the results of Table 3, hemoglobin and ferritin levels significantly decreased with age.
Table 2.Characteristics of the Elderly Living in Nursing Homes or Communitya
| Variable | All (N = 365) | NHR (N = 41) | CDOA (N =324) | OR (95% CI) | P Valueb |
|---|---|---|---|---|---|
| Age, y | 82.16 ± 5.79 | 80.44 ± 6.61 | 82.38 ± 5.65 | 0.94 (0.89 - 0.99) | 0.045 |
| Age groups, y | 0.61 (0.35 - 1.05) | 0.077 | |||
| 60 - 69 | 13 (3.6) | 4 (9.8) | 9 (2.8) | ||
| 70 - 79 | 125 (34.2) | 15 (36.6) | 110 (34.0) | ||
| ≥ 80 | 227 (62.2) | 22 (53.7) | 205 (63.3) | ||
| Marital status | |||||
| Single | 27 (7.4) | 6 (14.6) | 21 (6.5) | 2.47 (0.93 - 6.54) | 0.068 |
| Married | 338 (92.6) | 35 (85.4) | 303 (93.5) | ||
| Number of children | 5.91 ± 2.33 | 4.53 ± 2.39 | 6.08 ± 2.26 | 0.79 (0.70 - 0.89) | 0.0001 |
| Number of female children | 3.27 ± 1.55 | 1.68 ± 1.23 | 3.48 ± 1.47 | 0.48 (0.38 - 0.60) | 0.0001 |
| Number of male children | 2.66 ±1.28 | 2.87 ±1.51 | 2.63 ± 1.25 | 1.16 (0.89 - 1.50) | 0.263 |
| Hemoglobin, g/dL | 12.51± 1.04 | 12.00 ±1.05 | 12.57 ±1.02 | 0.60 (0.44 - 0.82) | 0.001 |
| Normal (≥ 120) | 258 (70.0) | 25 (61.0) | 233 (71.9) | ||
| Mild (110 - 119) | 84 (23.9) | 9 (22.0) | 75 (23.1) | ||
| Moderate (80 - 109) | 22 (6.01) | 7 (17.1) | 15 (4.6) | ||
| Severe (< 80) | - | - | - | ||
| Serum ferritin, µg/L | 15.71 ± 5.11 | 11.13 ± 3.15 | 16.28 ± 5.02 | 0.68 (0.60 - 0.77) | 0.0001 |
Abbreviations: CI, confidence interval; OR, odds ratio; SD, standard deviation.
aValues are expressed as mean ± SD or No. (%).
bP < 0.05 was considered significant.
Table 3.IDA Parameters in the Studied Elderly Based on Agea
| Variable | NHR (N = 41) | CDOA (N = 324) | OR (95% CI) | P Valueb |
|---|---|---|---|---|
| Hemoglobin, g/dL | 0.60 (0.44 - 0.82) | 0.001 | ||
| 60 - 69 | 11.85 ± 1.36 | 13.23 ± 0.99 | ||
| 70 - 79 | 12.26 ± 0.92 | 12.70 ± 0.84 | ||
| ≥ 80 | 11.85 ± 1.09 | 12.47 ± 1.09 | ||
| Serum ferritin, µg/L | 0.68 (0.60 - 0.77) | 0.00001 | ||
| 60 - 69 | 12.5± 1.91 | 17.42 ± 8.60 | ||
| 70 - 79 | 11.42± 3.22 | 16.54 ± 4.38 | ||
| ≥ 80 | 10.68 ± 3.28 | 16.10 ± 5.16 |
Abbreviations: CDOA, community-dwelling older adults; CI, confidence interval; NHR, nursing home residents; OR, odds ratio; SD, standard deviation.
aValues are expressed as mean ± SD.
bP < 0.05 was considered significant.
In addition, based on the amount of hemoglobin (OR = 0.60, 95% CI = 0.44 - 0.82) or ferritin (OR = 0.68; 95% CI = 0.60 - 0.77), community-dwelling can be a preventive factor for anemia (Table 2). Another finding was that there was no significant relationship between marital status and living in nursing home. Meanwhile, having children, especially female, had a direct relationship with staying at nursing home (OR = 0.48; 95% CI = 0.38 - 0.60) (Table 2).
5. Discussion
IDA is a common complication in elderly females, especially the ones living in nursing homes, which prone the elderlies to disability and mortality. This is one of the first studies in Iran that compared the prevalence of IDA between elderly females living in nursing homes and community. In epidemiological studies, the most applicable definition for anemia in elderly females was hemoglobin level less than 12 g/dL (13) that was also considered in the current study. Anemia prevalence varies depending on environmental factors and the population and location under study (29). The reported prevalence of IDA in older people varies from 2.5% to 55%. IDA can be caused by blood loss, malignancy, or decreases in iron intake or iron absorption (29). Accordingly, the overall prevalence of anemia in females under study was 30% (28% in community dwellers and 39% in nursing home residents), which was different from the rate reported by Cecchi et al. (30), in Italy (24%) among the community-dwelling older females, Yusof et al. (31), in Malaysia (37.5%), Callera et al. (32), in the Southeastern Brazil (17.6%), Westerlind et al. (33), in Sweden (32%) among elderly females living in nursing homes, Chan et al. (34), in China (65%) and Sahin et al. (29), in Turkey (55%). Contradiction between the results can be related to differences in the populations studied, the criteria used to define the anemia, and the studies design.
Another result of the current study was the higher prevalence of IDA in the elderly females who lived in nursing homes compared to the elderly community dwellers, since in Bushehr, due to the cultural taboos of taking the elderly to the nursing home, they are only taken to such places when they live in desperately poor conditions and have comorbidities (35); hence, the higher prevalence of IDA can be explained in this group. In addition, living in the nursing home affects the nutritional status, mobility, and vulnerability of the residents, which exposes them to the risk of IDA; consistent with the results of the present study (29, 34, 36-39).
In the current study, the level of hemoglobin and ferritin decreased with age, and in particular in the nursing home residents caused by several reasons, including reduced erythropoietin secretion, reduced hematopoietic reserve, decreased intake of iron and vitamins, and the chronic illnesses that occur with chronic inflammatory diseases (30). The results of the current study were consistent with those of other studies (3, 4, 9, 13, 15, 29, 31, 33).
5.1. Strengths and Limitations
The strength of the current study was its being among one of the first studies to compare the prevalence of IDA between the elderly female community-dwellers and nursing home residents, and it had limitations such as small sample size of the subjects living in nursing homes (especially that only females were included), and disregarding the impact of underlying diseases, nutritional status, and residency time on IDA incidence. All these can be ascertained from a longitudinal study.
Due to the prevalence and importance of anemia in the elderly, especially the ones living in nursing homes, it is helpful to conduct further studies on the causes and risk factors of this complication and develop local guidelines to control it.
5.2. Conclusions
The current study results showed that IDA was one of the problems of elderly females, especially the nursing home residents, which confirmed the results of studies in other countries. Due to the health consequences and risk of mortality in elderly females with reduced hemoglobin, this index is recommended to be monitored on a regular basis. A national plan for screening and timely treatment of the elderly community dwellers and the ones referring to health houses should be undertaken to prevent complications such as frailty and disability in this group.
