Worldwide Prevalence of Occupational Exposure to Needle Stick Injury among Healthcare Workers: A Systematic Review and Meta-Analysis

Background Healthcare workers are at high risk of occupational exposure to needle stick injury worldwide. Occupational exposure to needle stick injury represents the most common sources of infection such as hepatitis B virus, hepatitis C virus, and human immunodeficiency virus. Thus, this review aimed to determine the career time and previous one-year global pooled prevalence of occupational exposure to needle stick injury among healthcare workers. Methods The review considered articles written in English language and published from 2012 to 2020. The articles were searched using nine electronic databases (PubMed, Google Scholar, CINAHL, MEDLINE, Cochrane library, Web of Science, SCOPUS, MedNar, and ScienceDirect) using a combination of Boolean logic operators (AND, OR, and NOT), Medical Subject Headings, and keywords. Quality assessment was performed to determine the relevance of the articles using Joanna Briggs Institute critical appraisal tools. Several steps of assessment and evaluation were taken to select and analyze the relevant articles. Results The worldwide pooled prevalence of needle stick injuries among healthcare workers during career time and previous one year was 56.2% (95% CI: 47.1, 64.9) and 32.4% (95% CI: 22.0, 44.8), respectively. The career time pooled prevalence of needle stick injuries based on the socioeconomic development and study area was 54.8% and 55.1%, respectively, and one-year pooled prevalence of needle stick injury was 26.0% and 20.9%. Conclusion The review found a high prevalence of occupational exposure to needle stick injury among healthcare workers and suggests the need to improve occupational health and safety services in the healthcare systems.


Introduction
Needle stick injuries (NSIs) are among the most common occupational hazards among healthcare workers (HCWs) worldwide that need to be addressed and represent the most common sources of infection [1]. Infectious complications related to occupational exposure to NSI can result in serious health problems ranging from mild to extreme anxiety [2].
Today, at least 20 different pathogens are transmitted by NSIs such as hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) [3,4]. Annually, hundreds of thousands of HCWs are at high risk of work-related infections such as HBV, HCV, and HIV as a result of exposure to contaminated needle sticks and sharp injuries [5,6]. Furthermore, the risk of infections from NSIs ranges from 0.2 to 0.5% for HIV, 3-10% for HCV, and 40% for HBV [7].
According to Centers for Disease Control and Prevention (CDC) and European Agency for Safety and Health at Work, more than 385,000 and one million NSIs cases are reported annually among HCWs working in hospitals in the United States and Europe, respectively [8,9]. Worldwide, about three million of HCWs were exposed to blood pathogens through percutaneous, of which two million were exposed to HBV, 0.9 million exposed to HCV, and 170,000 exposed to HIV of which more than 90% occurred in developing countries [10][11][12].
World Health Organization (WHO) estimated that NSIs cause HCV that account 16,000, HBV that account 66,000, and HIV that account 1,000 annually among HCWs [13].
Determining the worldwide prevalence of needle stick injury among HCWs is necessary, particularly in reducing NSI, creating safer working conditions and cultures, reducing costs, and provision of higher quality services [15][16][17].
Prior to this study, many studies have reported the prevalence of NSI among healthcare workers at the country, regional, or institutional level [18][19][20][21][22]. Also, there are a few studies that provide worldwide evidence of the prevalence of occupational exposure to NSIs among HCWs and reported one-year prevalence alone [1].
us, this study aimed to determine and provide the worldwide pooled prevalence of needle stick injury (both one year and career time prevalence) among healthcare workers that are very important for understanding the problems and designing prevention program including occupational health and safety practices and standard precautions.

Eligibility Criteria.
e articles that met the following inclusion criteria were included in the systematic review and meta-analysis: (i). Study Design. Cross-sectional studies (ii). Outcome. Studies that provide quantitated outcomes (magnitude, frequency, or prevalence of NSI) (iii). Study Area. Studies conducted in developed and/ or developing countries (iv). Language. Full-text articles published in the English language (v). Population. Healthcare workers and medical students regardless of their occupation (vi). Publication Issue. Articles published in peerreviewed journals from 2012 to 2020 On the contrary, the studies reported period prevalence (such as 3 or/and 6 months) of NSIs, case reports, case series, qualitative studies, review articles, surveillance data/reports, conference abstracts, personal opinions, non-healthcare workers study participants, studies that utilized less than 120 participants, articles written in non-English language, high risk of bias articles, study not available in full texts, and studies published before 2012 were excluded from the study.
en, all identified keywords and an index term were checked across the included nine electronic databases. Finally, searching the reference list of all identified articles for further articles was conducted.

Study Selection.
Duplicated articles were removed using the ENDNOTE software version X5 ( omson Reuters, USA). e authors (DA. Mengistu, ST. Tolera, and YM. Demmu) screened the titles and abstracts of the identified articles by applying the inclusion and exclusion criteria. Finally, the review included only articles conducted to determine the prevalence of NSIs among healthcare workers in healthcare systems of developing or developed countries.

Quality Assessment.
Full-text articles, available in English language, with clear objectives and methodology, and studies including needle stick injury as a dependent variable and providing quantitative outcomes were selected. ese articles were then evaluated to confirm their relevance to the study and to confirm the quality of the work.
Furthermore, selected articles were subjected to a rigorous, independent appraisal using standardized critical appraisal tools (JBI Critical Appraisal tools) [23] to determine the quality and relevance of the articles. en, the score was taken across all studies and graded as high (85% and above score), moderate (60-85% score), and low (<60% score) quality. Disagreement made on what is to be extracted was solved by discussion. e PRISMA guidelines protocol [24] was used to conduct the review.

Data Extraction.
e authors (DA. Mengistu, ST. Tolera, and YM. Demmu) independently extracted data from the included articles. A predefined Microsoft Excel 2016 format was used to extract information from selected studies under the following headings: author, publication year, country of study, study design, and primary outcomes such as prevalence or magnitude of exposure to NSI and possible confounding factors considered. In general, all required data were extracted from the eligible articles.

Data Analysis and Statistical Procedures.
e prevalence of NSI was categorized into career time and 12-month prevalence. For those studies reporting the frequency of NSI without calculating the prevalence, the prevalence was calculated by dividing the frequency of exposed to the total sample size or multiplying the ratio of exposed to sample size. e pooled prevalence of both NSIS was done using Comprehensive Meta-Analysis (CMA) version 3.0 statistical software. e random-effect model and forest plot were used to estimate the pooled prevalence of needle stick injury among healthcare workers with 95% confidence intervals (95% CI). e possibility of publication bias was assessed by visual funnel plots, and a p value <0.05 was considered as the evidence for publication bias. Furthermore, subgroup analysis was conducted based on the countries where the articles were conducted, and socioeconomic development, to minimize the random variations (heterogeneity) between the point estimates of the included articles.

2.7.
Heterogeneity. In this study, Cochran's Q test (Q) and (I Squared test) I 2 statistics were used to evaluate the heterogeneity of the included articles. Furthermore, the differences among included articles were evaluated using graphical and statistical tests. en, the characteristics of the articles were described using texts, tables, and forest plots. Forest plot was used to evaluate the pooled prevalence of both NSIs. Subgroup analysis was done based on study area and socioeconomic development.

Study Selection.
A total of 3,018 studies published from 2012 to 2020 were identified. en, 976 duplicate articles were excluded, while 1,781 articles were excluded based on the exclusion criteria. Furthermore, 161 full-text studies were further assessed to determine their eligibility, of which 143 studies were excluded as they failed to report the prevalence of needle stick injuries, due to their unclear objectives, unclear methods, small sample size, and non-healthcare worker participants.
Finally, 18 articles that met the inclusion criteria were included in the review (Figure 1).

Career Time Prevalence of Needle Stick Injury.
e career time prevalence of occupational exposure to needle stick injury among healthcare workers was 56.2% (95% CI of 47.1 to 64.9), with I 2 � 96.474% and a p value < 0.001 ( Figure 2).
Based on a subgroup analysis by country where the studies are conducted, the lowest prevalence (29.8% (95% CI: 25.8, 34.2%) with a value of <0.001) of career time exposure to NSI among HCWs was observed in Saudi Arabia, whereas the highest prevalence (81.5%, (95% CI: 49.3-95.3%) with a p value of 0.05) was in Iran. e overall pooled prevalence of career time occupational exposure to NSI was 55.1% (95% CI: 53.3-56.8%) with a value of p < 0.001 (Figure 3).

Previous One-Year Prevalence of Needle Stick Injury.
e pooled prevalence of occupational exposure to needle stick injury among HCWs in the previous 12 months was 32.4% (95% CI: 22.0, 44.8 and a p value � 0.006) with I 2 � 98.76% and a p value of <0.001 ( Figure 5).

Discussion
Occupational exposure to NSIs is a major source for the transmission of blood-borne pathogens such as HBV, HCV, and HIV. However, the current review found the pooled prevalence of needle stick injury among HCWs during career time and previous one year accounted 56.2% and 32.4%, respectively. Also, we found a lower pooled    prevalence of the previous one-year needle stick injury than the prevalence of NSI injury reported by Bouya et al., 2020 (44.5%; 95% CI 33.7, 53.2) [1]. Auta et al., 2018 [42], also reported the one-year global pooled prevalence of percutaneous injuries that accounted 36.4% (95% CI: 32.9, 40.0) that was higher than our estimates. e pooled prevalence of needle stick injury among HCWs during their career time and in the previous one year varied based on publication year, socioeconomic development, and study area (country). is finding may be related to the variation in the application of standard procedures, occupational health and safety systems, availability and implementation of policies, poor NSI management, and unsafe working environments. e health problems related to occupational exposure to NSI such as HBV, HCV, and HIV infections were higher in developing countries [10,13,42,43]. Our review also found the pooled prevalence of NSIs during career time and previous one year among HCWs in developing countries was higher than in developed countries.
Overall, the review reported a high prevalence of NSIs among HCWs; thus occupational health and safety are crucial to reduce the risk of occupational exposure to NSI and the transmission of infectious diseases. Applying at least the following principles such as (1) establishing and implementing policies on NSIs management, (2) creating an appropriate safety and organizational culture, (3) applying standard precautions, (4) regular training on infection prevention and standard precautions, (5) regularly monitoring the proper implementation of guidelines, and (6) developing long-term NSIs reporting systems that play a great role in reducing NSIs and preventing infectious disease [1,10,[42][43][44][45].
Our review included studies from only fourteen countries. Most of these studies were conducted in developing countries, which limits the interpretation of results. Furthermore, the included articles were cross-sectional studies and the methodological limitations of such studies need to be considered when interpreting their results. Also, data from most studies were collected based on a self-reported  manner and this can affect the prevalence of needle stick injury due to reporting of exposure.

Conclusion
e review found a high prevalence of occupational exposure to needle stick injury among HCWs and suggests the need to improve occupational health and safety services in healthcare system globally. us, applying standard precautions, regularly training on infection prevention, and regularly monitoring the proper implementation of guidelines play a great role in reducing NSIs and preventing infectious diseases.

CDC:
Centers for Disease Control and Prevention CMA: Comprehensive meta-analysis HBV: Hepatitis B virus HCV: Hepatitis C virus HCWs: Healthcare workers HIV: Human immunodeficiency virus JBI: Joanna Briggs Institute NSI: Needle stick injury PRISMA: Preferred Reporting Items for Systematic Review and Meta-Analysis WHO: World Health Organization.

Data Availability
All the data are included in the systematic review and meta-analysis. In addition, PRISMA Protocols 2015 checklist is the recommended item to address in a systematic review and meta-analysis.

Conflicts of Interest
e authors declare that they have no conflicts of interest.

Authors' Contributions
DA. Mengistu conceived the idea and had major roles in the data review, extraction, and analysis. ST. Tolera and YM. Demmu also had a role in data extraction. All authors (DA. Mengistu, ST. Tolera, and YM. Demmu) contributed to analysis, writing, drafting, and editing, read and approved the final version to be published, and agreed on all aspects of this work.

Supplementary Materials
PRISMA-P (Preferred Reporting Items for Systematic Review and Meta-Analysis) 2015 checklist is one of the recommended items to address in a systematic review.