Distribution of Needlestick Injuries in Hand Parts: A Retrospective Cohort Study

Abstract

Background

A large number of healthcare workers worldwide experience needlestick injuries (NSIs), placing them at risk of infection. This study aimed to analyze the incidence of NSIs involving the hand, particularly focusing on the high incidence of NSIs in operating room staff, to provide a reference for the prevention of NSIs.

Material/Methods

We investigated the incidence of NSIs and the hand regions most frequently affected among operating room staff at a hospital in China from 2015 to 2023 using self-reported NSI data. Differences in NCI incidence across hand regions were analyzed using the chi-square test.

Results

Among the 139 NSI cases, 98 (70.5%) were attributed to the unsafe operation of medical devices, 128 (92.09%) occurred during procedures not involving surgical instruments, 87 (62.6%) were caused by swaged needles, and 46 (33.1%) occurred among staff involved in hepatobiliary and pancreatic surgeries. Of the 139 cases, 110 (79.1%) resulted in bleeding after NSIs. Regarding source infection status, 87 cases involved confirmed infections, 24 involved suspected infections, 9 had unknown infection status, and 14 had no infectious diseases. Regarding the effect of protective equipment, no statistically significant difference was found in the bleeding outcomes between individuals wearing single-layer and dual-layer gloves (P > 0.05), nor in the distribution of injury sites across different hand regions (P > 0.05).

Conclusions

Using local protective measures, such as medical gloves with stab-resistant or thickened materials in the index fingers and dorsal hand regions, may be an effective preventative measure against NSIs.

Introduction

Needlestick injuries (NSIs) are a prevalent occupational hazard posing significant risks to healthcare workers. Studies indicate that approximately 3 million healthcare workers experience NSIs annually. The most severe consequence is the transmission of bloodborne pathogens, which exposes workers to infections such as hepatitis B virus, hepatitis C virus, and HIV. Notably, NSIs are estimated to account for 39% of hepatitis C virus transmissions, 37% of hepatitis B virus transmissions, and 4.5% of HIV transmissions in occupational settings. Beyond the immediate physical trauma and pain, the requisite post-exposure prophylaxis often entails complex regimens that can lead to substantial physiological and psychological distress [1,2]. Furthermore, NSIs impose a considerable economic burden. Research by Mannocci et al estimates the average cost of a single NSI at 747 euros [3–6]. However, when factoring in potential infection treatment and long-term occupational impact, the indirect costs escalate significantly over time [7]. Critically, nurses, who are considered to be the backbone of the medical system, represent the largest proportion of healthcare workers experiencing NSIs, making them the group most burdened by this occupational hazard [8].

The high incidence of NSIs is multifactorial, stemming from unsafe practices, such as needle recapping, fatigue due to prolonged working hours, high-pressure emergency settings, and insufficient training in infection control [5]. Unfortunately, universally effective prophylactic strategies for NSIs remain elusive. Preoperative interventions, such as rigorous surgical training and strict adherence to regulatory protocols, can mitigate risks at the source; however, their efficacy is heavily contingent upon the management standards and enforcement capabilities of individual institutions. Similarly, although safety-engineered devices, such as retractable syringes, are designed to prevent inadvertent needlesticks, their high cost often limits their adoption by hospitals [9–15].

Given that the handling of sharp instruments inherently places the hands—the primary site of NSIs—at high risk, gloves function differently from the aforementioned strategies. As the most basic and economical physical barrier, they offer extensive applicability and high user acceptance [3]. Given the limited puncture resistance of single-layer gloves, double gloving was once viewed with high expectations [13,14,16]. Nevertheless, this intervention faces substantial practical barriers. Although some studies support its protective efficacy, clinical evidence indicates that double gloving significantly diminishes tactile sensitivity and manual dexterity while increasing hand fatigue [15,17,18]. Consequently, despite theoretical benefits, its clinical uptake remains limited among healthcare workers.

Understanding the anatomical distribution of NSIs is pivotal to addressing these persistent challenges. Evidence suggests that NSIs are not randomly distributed across the hand, showing rather that they exhibit distinct site-specific patterns [19]. However, current literature remains limited and lacks a consensus regarding the precise distribution of these injuries. For instance, while some studies identify the index finger, particularly the volar aspect, as the area at greatest risk, others, such as the research by Guo et al, highlight the thenar web space as the most vulnerable region [20]. This discrepancy underscores the necessity of further investigation into the topographic mapping of NSIs. Such research is essential for designing next-generation zone-specific protective gloves that balance enhanced safety with the preservation of tactile sensitivity.

In this study, we retrospectively collected and analyzed NSI data reported by operating room staff at West China Hospital of Sichuan University between 2015 and 2023. Using univariate analysis and chi-square testing, we evaluated the associated risk factors and generated a detailed topographic map of hand injuries to identify high-risk zones.

Material and Methods

Study Design and Setting

This was a retrospective descriptive study conducted in the operating rooms of West China Hospital, Sichuan University, from January 2015 to December 2023. The study aimed to describe the epidemiological characteristics, anatomical distribution, and associated risk factors of NSIs among operating room healthcare workers.

Data Source and Collection

Data were retrieved from the hospital’s Occupational Exposure Registry System. All cases included in this study were based on self-reported NSI records, which were completed by healthcare workers immediately after sustaining an injury and receiving emergency post-exposure treatment. Each record was subsequently verified and registered in the official logs.

Variables and Definitions

The key variables—unsafe operation, anatomical distribution, and demographic information—were predefined according to the registry protocol, as follows. (1) Unsafe operation was defined as any behavior that deviated from the standardized operating procedures outlined in preoperative training materials or official clinical guidelines, such as improper handling of sharps during instrument transfer or cleanup. (2) For anatomical distribution, the hands of each participant were divided into specific zones based on a predefined numbering system, as shown in Figure 1A. (3) For demographic information, recorded variables included professional role (eg, nurse trainee, regular nurse), sex, age group, and years of work experience.

Figure 1.

(A) Schematic diagram showing the anatomical division of the hands for injury localization. The 10 fingers are numbered 9, 10, 11, 12, 14, 15, 17, 18, 19, and 20; palm areas are numbered 8, 13, 16, and 21; the backs of the hands (including nail gaps) are divided into 14 parts, numbered 1–7 and 22–28. (B) Proportional distribution of NSI cases among the anatomical regions of the hands: fingers (63.8%), backs of hands (28.3%), and palms (8%). (C) Proportional distribution of NSI cases among different fingers: index finger (42%), middle finger (15.9%), ring finger (9.1%), little finger (3.4%), and thumb (29.5%).

Ethical Considerations

This study was approved by the Ethics Committee of West China Hospital, Sichuan University. To protect participant privacy, all personally identifiable information, such as name, employee ID, and specific contact details, was removed prior to data extraction. The dataset was anonymized, and only de-identified variables relevant to the research objective were retained for statistical analysis.

Inclusion and Exclusion Criteria

The inclusion criteria were all healthcare workers who sustained NSIs while on duty in the operating room and were formally recorded in the registry between 2015 and 2023. The exclusion criteria were records with incomplete critical data regarding injury location or mechanism, or entries that could not be objectively verified.

Statistical Analysis

For comparative analyses, categorical variables were compared using the chi-square test or Fisher exact test, as appropriate. To quantify the strength and precision of associations, odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were calculated for key comparisons (eg, glove use vs injury outcomes; injury site vs protective measures).

Multiple logistic regression analysis was employed to identify independent risk factors associated with bleeding and injury sites, using specific categories, such as finger injuries, as reference groups.

All statistical analyses were performed using SPSS version 27.0 and R version 4.4.1. A 2-tailed P value < 0.05 was considered statistically significant.

Results

Incidence of NSIs

The number of operating room staff increased yearly; however, the incidence of NSIs showed a decreasing trend, reaching its lowest point in 2023, as shown in Figure 2A. Among the 139 cases, 19 (13.7%) occurred in men and 120 (86.3%) occurred in women; 98 (70.5%) were caused by unsafe operation of medical devices, and 106 (76.3%) were punctures by needles. Regarding the procedures during which injuries occurred, 11 (7.91%) occurred in procedures involving the use of surgical instruments, and 128 (92.09%) occurred in procedures not involving the use of surgical instruments. Regarding the time of occurrence, 93 (66.9%) occurred between 8: 00 AM and 5: 59 PM, as shown in Table 1. As shown in Figure 2B, 62.6% of NSIs were caused by swaged needles, followed by indwelling needles, hypodermic needles, scalpels, medical scissors, and other surgical instruments. Regarding the distribution of NSIs among operating room staff across different types of surgeries, 46 (33.1%) occurred in staff involved in hepatobiliary and pancreatic surgeries, accounting for the largest proportion. In contrast, operating room staff for interventional surgeries (cardiac surgeries) and natural orifice surgeries (urology surgeries) had low incidences of NSIs, as shown in Figure 2C.

Figure 2.

(A) Temporal trends of needlestick injuries (NSIs) among operating room staff from 2015 to 2022. The graph displays 3 indicators: the annual incidence probability (prob, red line), the total number of surgical procedures (total number, green line), and the absolute number of NSI cases (injury number, blue line); (B) Proportional distribution of NSIs caused by different medical devices. Swaged needles accounted for most (62.6%), followed by other surgical instruments (15.8%), scalpels (6.5%), hypodermic needles (7.2%), IV catheters (4.3%), and medical scissors (3.8%). (C) Distribution of NSI cases across different surgical specialties. Hepatobiliary and pancreatic surgery had the highest incidence (33.1%), followed by gastroenterology (11.5%), orthopedics (8.6%), urology (8.6%), and other specialties as indicated in the legend.

Table 1.

Distribution of demographic and operational characteristics of 139 needlestick injuries.

Item	n	%
Sex
Male	19	13.7
Female	120	86.3
Unsafe operation of medical devices
Yes	98	70.5
No	41	29.5
Devices causing injuries
Needles	106	76.3
Non-needle devices (such as scissors, scalpels, and other surgical instruments)	33	23.7
Work procedures where injuries occurred
Procedures involving the use of surgical instruments	11	7.91
Procedures not involving the use of surgical instruments	128	92.09
Time of occurrence
8: 00 AM to 5: 59 PM	93	66.9
6: 00 PM to 7: 59 AM	46	33.1

Infectious Diseases of Patients in NSI Cases

Only self-reported NSI cases from operating room staff eligible to enter the operating rooms were investigated in this study. Among the 139 NSI cases, 14 patients had no infectious disease. Of the remaining 125 patients, 87 had confirmed infections, 24 had suspected infections, 9 were of unknown infection status, and 5 were recorded as not involved (Table 2). Particularly, 74 (53.2%) patients were infected with the hepatitis B virus, and 33 (23.7%) with syphilis. Moreover, 110 (79.1%) operating room staff had bleeding after NSIs (Table 2).

Table 2.

Distribution of infectious diseases carried by patients in needlestick injuries and bleeding in healthcare workers after injury.

Item	n	%
Infectious diseases in patients
Hepatitis B virus	74	53.2
Hepatitis C virus	9	6.5
HIV	2	1.4
Syphilis	33	23.7
Human papillomavirus	1	0.7
Hepatic hydatid disease	1	0.7
Hepatitis B virus and syphilis	1	0.7
Acinetobacter baumannii	1	0.7
Not involved	1	0.7
Unknown	2	1.4
No infectious diseases	14	10.1
Bleeding caused by needlestick injuries
Yes	110	79.1
No	29	20.9

Potential Factors Associated With NSIs

Among the operating room staff in the 139 cases, 77 (55.4%) had between 0 and 2 years of work experience. Similarly, 77 (55.4%) were below the age of 25 years. In terms of staff type, 63 (45.3%) were nurses undergoing standardized nurse training, and 46 (33.1%) were regular nurses at the study hospital. A total of 104 (73.9%) NSI cases occurred due to the device operators’ own reasons. In terms of the number of glove layers, 71 (51.08%) wore dual-layer gloves. The bleeding outcome did not differ significantly between individuals wearing single-layer and dual-layer gloves (P = 0.449, OR = 0.73, 95% CI: 0.32–1.65; Table 3). Similarly, the number of operators (individual vs joint operation) showed no significant impact on bleeding incidence (P = 0.340, OR = 1.28, 95% CI: 0.57–2.90). Further investigation into the determinants of unsafe medical device operation revealed no statistically significant differences across various subgroups. No significant associations were found when stratified by work procedures, age groups, years of work experience, or staff type (all P > 0.05; Table 4).

Table 3.

Logistic regression analysis to explore the influence of glove layers and number of operators on bleeding after needlestick injury.

		Bleeding		OR (95% CI)	P
		Yes	No
Number of glove layers	Single-layer	52	16	Reference	0.449
	Dual-layer	58	13	0.73 (0.32–1.65)
Number of device operators	Individuals operating the devices alone	56	13	Reference	0.340
	Individuals operating the devices jointly	54	16	1.28 (0.57–2.90)

Odds ratios (OR) and 95% CIs were calculated using the single-layer group and the individuals operating the devices alone as the reference.

Table 4.

Single factor analysis of unsafe medical device handling.

		Unsafe operation of medical devices		OR (95% CI)	P
		Yes	No
Work procedures	Procedures involving the use of surgical instruments	7	4	Reference	0.732
	Procedures not involving the use of surgical instruments	91	37	1.23 (0.35–4.32)
Work experience	0–2 years	56	21	Reference	0.365
	≥ 3 years	42	20	0.79 (0.39–1.61)
Age	< 25 years	56	21	Reference	0.303
	≥ 25 years	42	20	0.79 (0.39–1.61)
Staff type	Regular nurses	29	17	–	0.391
	Nurse interns	4	3	–
	Nurses receiving standardized nurse training	47	16	–
	Visiting nurses	18	5	–

Odds ratios (OR) and 95% CIs were calculated using the following groups as reference: group using surgical instruments, group with 0–2 years of work experience, and the group aged < 25 years.

Distribution of NSIs in Hand Regions

Of the 139 NSI cases, 138 occurred in the hands, indicating that the hands are the most vulnerable sites for NSIs. Of the 138 cases that occurred, 88 (63.3%) were in the left hand and 51 (36.7%) in the right hand. In this study, the hands of each investigated operating room staff were divided into different parts. The 10 fingers were numbered 9, 10, 11, 12, 14, 15, 17, 18, 19, and 20. The 4 parts in the 2 palms were numbered 8, 13, 16, and 21. The backs of the 2 hands (including gaps around the fingernails) of each participant were divided into 14 parts, numbered 1, 2, 3, 4, 5, 6, 7, 22, 23, 24, 25, 26, 27, and 28, as shown in Figure 1A. Twenty-nine NSI cases occurred in part 17, and 18 NSI cases occurred in part 15. The number of NSI cases that occurred in other parts of a pair of hands was less than 10. NSI cases occurring in fingers accounted for the largest proportion (63.8%), followed by the backs of the hands (28.3%) and palms (8%), as shown in Figure 1B. For NSI cases that occurred in fingers, those in the index fingers accounted for the largest proportion (42%), as shown in Figure 1C. No statistically significant differences were found in the distribution of injury sites between individuals wearing single-layer and dual-layer gloves (P = 0.269). As shown in Table 5, compared with finger injuries (reference group), wearing dual-layer gloves did not significantly alter the risk of injury to the backs of the hands (OR = 0.87, 95% CI: 0.43–1.77) or the palms (OR = 0.82, 95% CI: 0.24–2.82).

Table 5.

Association between injury site and wearing dual-layer gloves.

Injury sites	Wearing dual-layer gloves	Wearing single-layer gloves	OR (95%CI)	P
Fingers, n	46	42	Reference	0.269
Backs of the hands (including fingernail’s gaps), n	19	20	0.87 (0.43–1.77)
Palms, n	5	6	0.82 (0.24–2.82)

Odds ratios (OR) and 95% CIs were calculated using the finger injury group as the reference.

Discussion

The harm caused by NSIs cannot be underestimated. Incidences of NSIs show strong regional differences worldwide, with developing countries having a high incidence. The incidences among healthcare workers in Ethiopia, China, Mongolia, and Ghana were reported as 40.01%, 39.18%, 38.4%, and 29.7%, respectively [21,22], revealing a high incidence, which may be explained by the lack of effective protective measures in place to reduce the incidence of NSIs. Our study results revealed that the incidence of NSIs among operating room staff showed a decreasing trend, possibly due to the continuously optimized training system at the hospital. Unsafe operation of medical devices could cause NSIs, and NSIs could occur even during work procedures not involving the use of surgical instruments, such as passing sharp instruments and collecting and organizing sharp instruments during and after surgery. These findings are similar to the results of Foster et al who conducted a similar study in Jamaica [22].

Although our hospital has been strengthening and improving staff training, eliminating unsafe operation of medical devices among operating room staff remains challenging, as device operators have varying levels of familiarity and mastery with device operation methods, and they may work in different scenarios, such as emergency situations. Therefore, only formulating operating procedures and providing staff training have limitations in actual situations. For the types of medical devices that caused NSIs, we found that swaged needles caused the largest proportion of NSIs among operating room staff, which differs from the results of Kable et al in New South Wales, Australia, who reported that hollow-bore needles bring the greatest risk of NSIs [23]. This is possibly because we compared studies in different healthcare systems and with different study participants. Our study found that operating room staff involved in hepatobiliary and pancreatic surgeries had the highest incidence of NSIs, while those involved in interventional and natural orifice surgeries had a low incidence of NSIs among the investigated participants. This is possibly because different surgical procedures employ varying surgical methods, densities, and frequencies of sharp device contact.

In this study, most operating room nurses who had NSIs were in contact with patients with infectious diseases, such as hepatitis B virus and syphilis. This made it necessary for the nurses to get vaccinated after NSIs, thereby bringing additional financial expenditures and affecting their mental well-being. Fortunately, the study hospital has relatively complete preventive measures, and these nurses were not infected with infectious diseases. However, in regions with limited resources and a high incidence of infectious diseases, inadequate NSI prevention systems may leave healthcare workers at increased risk of infection, potentially impeding progress in global health protection [24]. The current preventive system for responding to NSIs advocates education, the use of safety equipment, and improving post-injury treatment. However, the implementation of these measures has faced challenges since their introduction. The use of safety equipment is often limited by cost, and education and post-injury treatment are influenced by the availability and quality of medical care. Therefore, identifying strategies to effectively reduce the incidence of NSIs remains important.

Makeen et al, who conducted a comparative study of NSIs in secondary and tertiary hospitals in Saudi Arabia, reported differences in the incidence of NSIs among healthcare workers between secondary hospitals and tertiary hospitals in the same country, which they attributed to varying levels of medical treatment [25]. However, a 2011 survey on NSIs conducted in China did not reveal significant differences between secondary and tertiary hospitals [26]. This highlights differences between different countries. Previous studies have shown that the occurrence of NSIs is associated with the years of work experience of healthcare workers [27], which was not observed in our study. No statistically significant differences were found in the unsafe operation of medical devices across age, years of work experience, and staff type. This indicates that NSIs are common among healthcare workers. The results of a study conducted in Japan align with our findings, showing that the occurrence of NSIs is not associated with the years of work experience.

Among the 139 cases in this study, only 1 occurred in the wrist, and the remaining 138 occurred on the hands. The sites of NSIs were closely associated with the surgical tasks undertaken by operating room nurses. This study found that most NSIs occurred in work procedures that did not involve the use of surgical instruments, such as organizing, collecting, and passing surgical instruments. During these processes, sterile gloves serve as an important barrier to protect device operators. Strengthening this preventive measure is particularly important, as highlighted in this study. Through research on NSIs in the hands, we found that the fingers and the backs of the hands accounted for a large proportion of NSIs. For fingers, the index fingers had the largest incidence of NSIs, consistent with the findings of Fritzsche et al [28]. In addition, NSIs in the thumb accounted for a large proportion. Unlike our study, other studies lack research on different parts of the hands. Our study also found that NSIs were more common in the left hand (63.3%), as the non-dominant hand of operating room staff is more likely to come into contact with the sharp end of the device during use. As for the protective effect of dual-layer gloves, the results of Thomas et al and Singh et al showed that dual-layer gloves offer better protection than single-layer gloves against NSIs when worn by surgeons [29,30]. However, our study did not reveal an association between wearing dual-layer gloves and bleeding caused by NSIs, and wearing dual-layer gloves did not protect susceptible parts more effectively than single-layer gloves. The reason many device operators did not wear dual-layer gloves may have been their perception that these gloves would affect hand flexibility.

This study was conducted with the aim of minimizing the effects of varying levels of healthcare system development and economic status. Medical gloves are the most widely used equipment in healthcare settings. Improving medical gloves can reduce unnecessary psychological stress for healthcare workers during surgery. This study found that the index fingers and the backs of the hands were susceptible areas for NSIs. Using stab-resistant or thickened materials for gloves is a potentially effective way to prevent NSIs without affecting hand flexibility. Its advantages lie in its low cost and wide application.

Limitations

This study has some limitations. First, it is a single-center study with a relatively small sample size; future studies with larger sample size are needed. Second, the data were based solely on self-report, which may have led to underreporting of cases. Third, as a retrospective study relying on previous records, it may be subject to biases.

Conclusions

The incidence of NSIs among operating room staff at the investigated hospital remained below 10%. Most occurred in the left hand, increasing the risk of exposure to infectious diseases. Regarding hand parts, the index fingers were the most susceptible part to injuries. Using gloves with stab-resistant or thickened materials on the index fingers and backs of the hands may help minimize the risk of NSI occurrence. This is a potentially effective preventive measure for NSIs.