Frequency of anaemia in patients referred to internal medicine outpatient clinic and its relationship with sociodemographic factors

Authors

Abstract

Aim Anemia is recognized as a global public health issue. This study aimed to investigate the prevalence of anemia and its associations with selected sociodemographic factors among patients presenting to a tertiary care internal medicine outpatient clinic.
Materials and Methods This retrospective cross-sectional study included 8536 patients who presented to the Internal Medicine outpatient clinic of Harran University Faculty of Medicine Hospital between July 2023 and July 2024. Data were obtained through the review of hospital records to determine the prevalence of anemia and its association with sociodemographic characteristics. The analysis of the obtained data was performed using SPSS version 26.0.
Results Among the 8536 patients included in the study, 2630 (30.8%) were male and 5906 (69.2%) were female. The mean age of the participants was 40.9±17.7 years (range:15–97). Iron deficiency anemia (IDA) was observed in 18.4% of women of reproductive age, 10.7% of postmenopausal women, and 3.3% of men; this difference was statistically significant (p<0.001). Vitamin B12 deficiency anemia was detected in 1.6% of women of reproductive age and 0.6% of men, also demonstrating a statistically significant difference (p=0.004). Folate deficiency anemia showed a low prevalence across all three groups (0.6–0.7%) with no significant difference between sexes (p=0.837).
Discussion The findings provide valuable data for shaping regional health policies and for developing screening and prevention strategies targeting at-risk populations. Regular screening programs, especially for women of reproductive age, along with planned iron and vitamin supplementation and the widespread implementation of nutritional education, are strongly recommended.

Keywords

Introduction

Anaemia is a systemic condition defined by a decrease in the number of erythrocytes carrying oxygen to the body and/ or haemoglobin concentration below the reference levels determined according to age and sex, and is one of the important public health problems, especially in developing countries [1, 2]. Anaemia may lead to many clinical and functional problems, including fatigue, distraction, cognitive impairment, susceptibility to infection, and loss of labour force, and may negatively affect quality of life [3]. Iron deficiency stands out as the most common cause of anaemia worldwide.
In particular, iron deficiency anaemia (IDA) is the most common type of anaemia in both developed and developing countries, and malnutrition, chronic blood loss, and malabsorption constitute the most common causes [1]. According to the World Health Organisation, approximately two billion people are estimated to be deficient in one or more micronutrients, and women of childbearing age, pregnant women, and children living in low- and middle-income countries are particularly affected [4, 5]. The prevalence of anaemia in women of childbearing age worldwide has been reported to be approximately 30%; this rate is considerably higher compared to men, making women a special risk group in this respect [6].
In Şanlıurfa, one of the provinces with the highest fertility rate in Turkey, the average number of children per woman is 3.28. At the same time, according to the data of the Turkish Statistical Institute, Şanlıurfa ranks 73rd in the country in terms of socioeconomic development level, and it is thought that this situation may have negative effects on the nutritional status of individuals in the region and their access to health services. Internal medicine outpatient clinics are health units that have an important role in the early diagnosis and referral processes of systemic diseases such as anaemia. Anaemia can often be detected in outpatient clinic examinations as the first symptom of another disease, and allows the underlying causes to be revealed with correct guidance. In light of this information, this study aims to evaluate the prevalence of anaemia in individuals aged ≥18 years admitted to the Internal Medicine Outpatient Clinic of Harran University Faculty of Medicine Hospital and to examine the relationship between the presence of anaemia and basic demographic factors such as age and gender.

Materials and Methods

This cross-sectional-retrospective study was conducted on the data of a total of 8536 patients who were admitted to the Internal Medicine Outpatient Clinic of Harran University Faculty of Medicine Hospital between July 2023 and July 2024 and whose laboratory records included complete blood count and related biochemical parameters. Data were obtained from the hospital information management system. Individuals aged ≥15 years were included in the study. Individuals younger than 15 years of age, pregnant women, patients with active malignancy, and patients with known haematological malignancies were excluded from the study. Individuals diagnosed with IDA, vitamin B12 deficiency anaemia, and folic acid deficiency anaemia, along with individuals without anaemia, were included in the analysis.
The diagnosis of anaemia is accepted as haemoglobin <13 g/dL in males and <12 g/dL in females according to World Health Organisation criteria [7]. The diagnosis of IDA was made according to the criteria of low ferritin level (<30 ng/ mL), transferrin saturation <20%, low serum iron level, and high total iron binding capacity (UIBC). Vitamin B12 deficiency anaemia is defined as a serum B12 level of <211 pg/mL, and folic acid deficiency anaemia is defined as a serum folate level of <5.38 ng/mL; this condition is associated with elevated MCV (>100 fL) [8]. The data obtained were analysed with SPSS 26.0 software (IBM Corp., Armonk, NY). The prevalence was calculated in each group according to the presence of anaemia, and the results were expressed as a percentage (%). The Chi- square test was used to compare the prevalence of anaemia between groups. Continuous variables were presented as mean ± standard deviation if normally distributed and median (minimum-maximum) if not normally distributed. Categorical data were expressed as numbers and percentages. One-way analysis of variance (One-way ANOVA) was used to compare continuous variables when parametric assumptions were met. Bonferroni correction was applied to reduce the risk of error in multiple comparisons; the significance level was accepted as p<0.01 for three pairwise comparisons between three groups. Necessary institutional permission was obtained from the Chief Physician’s Office of Harran University Hospital for the evaluation of laboratory and demographic data used in the study.
Ethical Approval
The study was approved by the Ethics Committee of Harran University (Date: 2025-05-12, No: HRÜ/27.05.2025-447285). The study was conducted in accordance with the ethical principles stated in the Declaration of Helsinki.

Results

In this study, data from a total of 8536 patients were analysed. Of the participants, 69.2% were female (n=5906) and 30.8% were male (n=2630). Among the women, 69.6% (n=4110) were in the reproductive age group (15-49 years) and 30.4% (n=1,796) were in the postmenopausal period (≥50 years). The mean age of the participants was 40.9 ± 17.7 years, 30.9 ± 9.4 years in reproductive age women, 62.03 ± 9.31 years in postmenopausal women, and 42.34±17.14 years in men. When haematological and biochemical parameters were evaluated, haemoglobin levels were significantly higher in men (15.11±1.65 g/dL) than in postmenopausal women (13.01±1.54 g/dL) and reproductive women (12.68±1.62 g/dL) (p<0.001). Similarly, haematocrit levels were higher in men (45.68±4.6) compared to women (p<0.001) (reproductive women: 39.14±4.45; postmenopausal women: 40.30±4.4). The mean ferritin level was 76.64 ± 100.22 ng/mL in men, 56.56 ± 177.04 ng/mL in postmenopausal women, and 21.45±39.12 ng/mL in women of reproductive age (p<0.001). Serum iron level was significantly higher in men (87.17±40.55 µg/dL); this value was 63.17±31.04 µg/dL in postmenopausal women and 49.61 ± 29.3 µg/dL in women of reproductive age (p<0.001). Transferrin saturation was 47.24±54.7% in men, 27.81±39.28% in women of reproductive age, and 27.11±32.34% in postmenopausal women (p<0.001). Demographic characteristics and haematological-biochemical parameters are shown in Table 1.
When the distribution according to anaemia types was analysed, the prevalence of IDA was found to be 12.1% and it was 18.4% in reproductive age women, 10.7% in postmenopausal women, and 3.3% in men, and this difference was statistically significant (p<0.001). B12 deficiency anaemia was seen in 1.6% of reproductive age women and 0.6% of men, and this difference was statistically significant (p=0.004). Folic acid deficiency anaemia had a low prevalence in all three groups (0.6-0.7%), and there was no significant difference between genders (p=0.837). Detailed anemia subtypes of the participants according to age group and gender are presented in Table 1.

Discussion

Anaemia is an important health problem due to its prevalence and clinical effects in both developed and developing countries worldwide. Global estimates of the burden of anaemia are of great importance for the development of appropriate interventions to achieve current international targets for the reduction of the disease [9]. In our study, the prevalence of IDA was found to be 12.1% and this rate was remarkable, with a two-fold higher rate in female patients compared to male patients. In a similar retrospective study, Chen et al. reported the prevalence of anaemia as 7.6%, and the rate of male participants was found to be higher than that of females in this study [10]. The high rate of women in the reproductive age group in our study may be considered the main reason for the higher-than-expected frequency of anaemia. In epidemiological studies conducted in different regions of Turkey, it has been reported that the rate of IDA varies between 11.5% and 13.5% and this condition is most frequently observed in women in the reproductive age group [11, 12]. Women are at high risk for anaemia because hormonal activities such as menstruation and pregnancy increase iron requirements [13]. The frequency of iron deficiency starts to increase again during adolescence, especially in women, when iron losses during menstruation overlap with the need for rapid growth. Since 1 mL of blood loss turns into 0.5 mg iron loss, heavy menstrual blood loss (more than 80 mL per month in approximately 10% of women) greatly increases the risk of iron deficiency. In addition, factors such as a high number of births, use of an intrauterine device, and malnutrition are also known to increase this risk [14]. In our study, 18.4% of women in the reproductive age group had anaemia, and this was the highest rate of anaemia in our study group. Similarly, 21.4% in Cuba and 25% in Pakistan were found to be anaemic in studies related to the incidence of intrauterine devices in women in the reproductive age group, indicating that this age group is particularly predisposed to anaemia [15, 16]. Vitamin B12 deficiency anaemia was observed more frequently in women than in men in our study, and this difference was found to be statistically significant. In a study conducted in Saudi Arabia, B12 deficiency was reported with a rate of 9.1% in women and 5.9% in men; in a study conducted by Koenig et al. in Europe, this rate was reported as 14.85% in women and 10.51% in men [17, 18]. It was suggested that this difference might be related to the pregnancy process, increased iron and B12 requirements of women, and higher meat consumption of men in some cultural dietary habits.
Folate deficiency anaemia was observed with a lower frequency in our study, and no significant difference was observed between genders. In studies conducted in China (4.7%) and Iran (1%) in adult age groups, it was reported that folate deficiency anaemia was less frequent compared to IDA and vitamin B12 deficiency anaemia, but it was observed more frequently in males than females, similar to our study [19, 20]. The lack of a significant difference between genders in our study may be due to interregional nutritional differences and the high fertility potential of women in this region, and the high use of folic acid supplements during pregnancy [21, 22].
In general, one of the important factors affecting the prevalence of anaemia is socioeconomic level. Low income level, lack of education, inadequate access to health services, and unbalanced nutrition increase susceptibility to anaemia [23]. The high prevalence of anaemia in socioeconomically disadvantaged regions with high fertility rates and high refugee density, such as Şanlıurfa, indicates that this is a priority problem in terms of public health.

Limitations

This study has some limitations. Firstly, due to the retrospective design, data were analyzed only from available records, which limits the evaluation of potential influencing factors such as dietary habits, pregnancy history, and amount of menstrual bleeding. Furthermore, since the study was conducted in only one center, the findings should be interpreted with caution in terms of generalizability. The fact that folate and B12 levels were only requested in some patients may not fully reflect the true prevalence of deficiency rates.

Conclusion

This study revealed that the prevalence of IDA and vitamin B12 deficiency in individuals presenting to the Internal Medicine Outpatient Clinic of Harran University Faculty of Medicine Hospital was significantly higher, especially in women of reproductive age. The findings obtained provide important data for shaping regional health policies and developing screening and prevention strategies for groups at risk. It may be recommended that regular screening programmes should be implemented, iron and vitamin supplements should be planned, and nutritional education should be disseminated, especially in women of reproductive age.

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