Journal of Health Scope
Volume:11 Issue: 1, Feb 2022

Exhaust noise is known to be a major pollutant in the environment and workplaces due to the development of industry and transportation. Exhaust noise can be reduced to normal levels by mufflers or silencers. A reactive muffler efficiently dampens noise at low frequencies by reflecting sound waves. Therefore, muffler design is of great importance in exhaust noise reduction. Transmission loss (TL) is an essential characteristic of mufflers, demonstrating their acoustical properties. Any acoustical appliance is selected based on its damping performance and reliability. Predicting TL through experimentation is different from theoretical calculations.

In the present study, a double-expansion chamber muffler was designed as a reflective muffler on a laboratory scale by equations. Next, TL was evaluated by an impedance tube applying a 4-microphone technique to determine the acoustical performance of the designed muffler.

Findings revealed that the TL of the muffler at 312 Hz frequency obtained 27.5 dB agreement with the required TL of the muffler of 25 dB. In addition, the TL of the muffler against frequency attenuates noise in broadband frequencies.

These results indicated that the built muffler provides desired TL for exhaust chambers. Therefore, equations can be used as a precise method for muffler design. Furthermore, multi-expansion chamber mufflers are useful for reducing noise at a wide range of frequencies. Keywords

Rationality is a complex concept that plays a vital role in human choices and decisions. However, this issue has been less addressed in studies on marital life.

This study was performed to explain the experiences of Iranian women on the verge of divorce regarding rationality.

According to the five-stage Granheim and Landman’s approach, an inductive conventional qualitative content analysis was used to collect and analyze women’s experiences on the verge of divorce. Seventeen women selected through purposive sampling entered the study, and qualitative information was collected using unstructured and semi-structured interviews. Information collection and analysis proceeded simultaneously. The information was saturated with 17 participants, and no new information was extracted. In this study, Lincoln and Guba’s criteria were used to ensure the robustness of the study.

After information analysis, two main themes were derived. Limited rationality in marriage was the first one with three main categories: Lack of intellectual preparedness for marital life, irrational marriage decision-making, and unrealistic positive thinking. Lack of marital issues understanding was the second one, categorized into reality shock and negative cognitive-emotional experiences.

This qualitative study showed that limited rationality plays a vital role in the lives of women on the verge of divorce. However, learning skills, such as deep thinking and realistic thinking, can help women overcome limitations toward rationality and lack of marital issues understanding.

Manganese (Mn) is an essential element for the human body, but it can cause adverse effects on the Central Nervous System at high doses. Exposure to manganese fumes during welding can harm welders' health.

The current study aimed to measure manganese produced by shielded metal arc welding (SMAW) in the breathing zone air and blood of welders and investigate the relationship between manganese concentrations in air and blood.

In this descriptive-analytical cross-sectional study, 35 welders were enrolled as the exposed group and 40 office workers as the control group. Manganese concentration in air was measured according to NIOSH method 7301. Air and blood sample analyses were carried out by ICP-OES. Statistical analysis was performed with MINITAB 17. Data were analyzed using Pearson correlation coefficient, one-sample t-test, paired t-test, and logistic regression. The significance level was set at P < 0.05.

The mean concentration of welding respirable particles and manganese fumes were 9.56 ± 1.67 and 0.45 ± 0.08 mg/m3, three and 22 times the exposure limit recommended by ACGIH, respectively. Average manganese was significantly higher in the welders’ blood (0.16 ± 0.02 µg/mL) than in the controls’ blood (0.04 ± 0.002 µg/mL). There were strong and significant correlations between the welding respirable particles and manganese concentration in welders’ breathing zone and blood manganese levels. Also, with each year of work experience, the manganese concentration in the welders’ blood increased by 1.5%.

Welders are at risk of contamination with manganese. Manganese exposure reduction through more efficient ventilation systems, reducing welder’s exposure time, staff training, and appropriate respiratory protection equipment should be applied to reduce manganese exposure among welders and prevent health complications.

Anthropometry plays an important role in the ergonomic design of hearing protection equipment and its compatibility with the dimensions of the external ear and head of workers. Few studies have been conducted on the dimensions of the external ears and heads of workers in Iran with different ethnicities.

This study aimed to collect the anthropometric dimensions of the external ear and head of workers of two prominent ethnicities of Iran for the ergonomic design of earmuffs.

Following a cross-sectional design, this study was performed on 300 male workers (150 Turk and 150 Fars) aged 20 - 60 years. Anthropometric dimensions of the external ear and head were measured using a spreading caliper, camera, tripod, and tape measure. Photographs were analyzed using Digimizer V5.3.5 software, and data were analyzed using SPSS 21.

The mean age of Turk and Fars workers was 33.51 ± 5.41 and 33.95 ± 6.05 years, respectively. The ear shape was oval in more than half of the male workers of the two studied ethnicities. There was a positive correlation between anthropometric dimensions of head and ears in both ethnicities. The 95th percentile of the length and width of the pinna in Fars and Turk workers was larger than the average dimensions of inner ring earmuffs.

Hearing protection devices available in the Iranian market should be examined to fit the ear dimensions of different Iranian ethnicities. External ear anthropometric data obtained from this study can be used to redesign the earmuffs in Fars and Turk male workers.

This systematic review and meta-analysis aimed to assess the ratio of patients with hypertension for whom coronavirus disease 2019 (COVID-19) has been diagnosed in the world. In addition, the effect of COVID-19 on the outcomes of hypertension was evaluated.

To find articles published by July 2020, a comprehensive systematic search was carried out in five electronic databases, including PubMed, Scopus, Embase, and Web of Science. The meta-analysis entailed all relevant articles on the clinical and epidemiological features of patients with COVID-19. Two researchers independently reviewed the eligible post-selection studies, and finally, the discrepancies between the opinions of the two researchers were resolved by a third arbitrator. Two researchers independently examined the risk of bias using the Newcastle-Ottawa Scale.

The pooled prevalence of high blood pressure in patients hospitalized with COVID-19 worldwide was obtained as 31% (95% CI: 23 - 38%). The changes for hypertension prevalence in different studies included in the meta-analysis varied from 2 to 64%. Moreover, the results of subgroups analysis based on different countries demonstrated that the prevalence of hypertension in patients with COVID-19 in China and other countries was 29% (95% CI: 24 - 34%) and 32% (95% CI: 19 - 46%), respectively.

The evidence revealed that a health condition that commonly accompanies and affects the outcomes of COVID-19 is hypertension. Therefore, COVID-19 patients with hypertension should be given priority and benefit from a preventive, therapeutic approach. Furthermore, essential training should be provided by health policymakers.

Ischemic heart disease (IHD) is the leading cause of death and disability worldwide and in Iran, which imposes a heavy financial burden both on patient’s family and society.

This study aimed to analyze the direct medical costs of inpatients with IHD and its influencing factors in Iran in 2020.

The sample of this cross-sectional study included 41,357 patients with IHD selected from the hospital information system (HIS) of the Iran Health Insurance Organization from August 23, 2019, to June 20, 2020. The study used the claims data of these patients, which included their demographics, length of stay (LOS), intensive care unit (ICU) admission, hospital accreditation grade, hospital ownership type, and patient discharge status. The multiple linear regression model was employed to evaluate the relationship between hospitalization costs and the associated factors. All statistical tests were conducted at the significance level of P < 0.05 using the R 3.6.3 software.

The mean age of patients was 63.95 ± 12.63 years old, and most of them were male (54.4%). The mean hospitalization cost per patient and per day was 586.42 ± 472.51 USD and 103.64 ± 100.29 USD, respectively. Moreover, the mean LOS was 4.92 days. Drugs and consumable medical supplies, as well as nursing and hoteling services, had the highest shares of hospitalization costs (29.54% and 29.4%, respectively). The hospitalization costs of patients with IHD were higher among men (β = 1.24), age 61 - 70 years (β = 1.38), LOS ≥ 5 (β = 2.92), ICU admission (β = 1.62), Iranian health fund (β = 1.21), and private hospitals (β = 1.91). Top-grade and first-grade hospitals had higher costs compared to grade 2 (β = 0.67), grade 3 (β = 0.35), and grade 4 (β = 0.72) hospitals. Deceased patients had also higher costs than patients with complete recovery (β = 0.63), relative recovery (β = 0.59), follow-up (β = 0.51), transfer to other medical centers (β = 0.44), and discharge against medical advice (DAMA) (β = 0.62).

According to the results, shortening the LOS and controlling the high costs of drugs and consumable medical supplies are among the main strategies to reduce high hospitalization costs.

Hepatitis B virus (HBV) is a severe public health problem in Iran. This study was conducted to investigate the intrafamilial transmission of HBV in vaccinated children whose one or both parents were positive for hepatitis B surface antigen (HBsAg).

In a study with retrospective cohort design, 110 exposed cases with HBsAg-positive parent(s) were compared with 110 unexposed controls of the same sex and age groups. The participants were directly asked about demographic characteristics, medical history, and vaccinations. Blood samples were collected and analyzed for HBV infection markers using the ELIZA method.

Overall, 1.8% HBsAg (P = 0.15) and 13.6% hepatitis B core antibody (HBcAb) (P < 0.0001) positivity rates were detected in the exposed group. The hepatitis B surface antibody titer (HBsAb) showed that 34.5% of cases and 56.3% of controls had HBsAb levels > 10 IU/L. There was a significant difference in the protective HBsAb level between the two groups (P < 0.0001). There were significant associations between HBsAb level and gender in the exposed group and decreased HBsAb levels and age.

The high rate of positive HBcAb and HBsAg and decreasing HBsAb levels with age in this study indicate that routine childhood vaccination programs are inadequate in preventing HBV transmission and vaccine routes changing or further booster vaccination is essential. Effective case finding in vaccinated children with HBsAg-positive parents, intradermal vaccination, and hepatitis B immunoglobulin in newborns with HBsAg-positive fathers are suggested.

Health transformation plan (HTP) in Iran was established in 2014 to promote primary health care through expanding and strengthening the first level of services in urban and rural areas. The activities of physicians and their colleagues in comprehensive health service centers have increased access and improved community health. Conducting various studies on the urban physicians’ roles can help policymakers achieve the goals.

This study aimed to explain the role of physicians working in urban, comprehensive health service centers after implementing the HTP.

Participants in this qualitative study consisted of physicians, healthcare providers, managers, and experts, working in urban health centers selected by a purposive sampling method. The data were collected by semi-structured interviews. After data saturation, they were analyzed by conventional content analysis.

After interviewing 35 people and several stages of review, coding, and using the experience of experts, the data were classified into six main categories, 11 subcategories, and 33 codes. Factors influencing the role of physicians were service delivery, electronic health records, resources, community culture, monitoring, supervision, and practical suggestion. The participants expressed the workload, referral system, integrated electronic health record, financial resources, human resources, equipment, and public participation as some aspects related to the role of physicians.

Based on the current study, human and financial resources should be managed to retain the physicians in this plan. In addition, increasing the quality of services, improving electronic health records, and attention to public culture can be considered.

Patient safety is a major concern for health care professionals. Medication errors have been considered a major indicator of health care quality. The lack of pharmacological knowledge is a cause of medication error among nurses.

The purpose of this study was to investigate the relationship between pharmacological knowledge and the probability of medical errors in nurses working in Urmia hospitals in 2020.

This cross-sectional study included 490 nurses randomly selected from among those working in hospitals of Urmia in 2020. The data collection tool was a multiple-choice questionnaire about knowledge and pharmacological skills consisting of 3 sections: demographic information, nurses’ drug knowledge, and the confidence level of response in nurses. To analyze questions and hypotheses via SPSS version 21, the t-test and analysis of variance (ANOVA) were employed.

The highest pharmaceutical knowledge scores of nurses were related to methods of administration (2.9 ± 1.01 [72.56%]), and the lowest score was related to drug management (1.05 ± 0.63 [52.84%]). The mean of error probability was very low in 28.81% of nurses, low in 37.66%, high in 11.34%, and very high in 22.85%. Pharmaceutical knowledge had a significant relationship with gender, wards, type of hospital, and number of children (P < 0.05 for all).

Since the nurses’ level of pharmaceutical knowledge has an important role in the correct prescription of medicine, we suggest that nurse managers and educational supervisors in the field of nursing use in-service training programs and prepare training booklets and posters to promote nurses’ pharmaceutical knowledge in this field.

Knowledge, attitude, and practice of people, especially high-risk ones, are essential for managing COVID-19. Previous studies have shown that inappropriate knowledge and attitude may influence people's decisions.

This study aimed to evaluate the knowledge and attitudes of patients towards COVID-19 who called emergency medical service (EMS) while suffering from a chronic underlying disease, whether they were transferred to the hospital during the pandemic or not.

This cross-sectional study was conducted from 21 May 2020 to 20 June 2020 in Tehran, Iran. Using the registered data in the databank of the Tehran EMS center, eligible participants were selected and divided into transferred and non-transferred groups based on the recorded data. A valid and reliable questionnaire comprising four parts (demographic information, patients' knowledge about COVID-19, patients' attitude towards COVID-19, and patients' fear) was used. A researcher-made checklist was also used for recording the consequences and reasons for refusal. Select eligible individuals who agreed to enter the survey were interviewed by telephone.

Totally, 201 transferred patients and 158 non-transferred patients were enrolled. The mean age of the transferred group was lower than that of the non-transferred one (57.1 ± 16.1 vs. 62.0 ± 17.4 years; P = 0.006). The mean knowledge score was not statistically different between transferred and non-transferred patients (28.8 ± 5.7 vs. 28.2 ± 5.4; P = 0.320). The mean attitude score was lower in the transferred group than in the non-transferred group (0.75 ± 3.7 vs. 2.2 ± 3.5; P = 0.001). The mean fear score was higher in the non-transferred group than in the transferred group, but the difference was not statistically significant (16.0 ± 5.1 vs. 15.0 ± 5.6; P = 0.101).

Most participants in both transferred and non-transferred groups did not have sufficient knowledge of the disease, but the average attitude had a positive score.