Keywords
diabetes - insulin - prefilled pens - syringes - preference - Islamabad
Introduction
Diabetes is a chronic metabolic condition characterized by elevated blood glucose levels, causing damage to various organs over time. Globally, there is a projected increase in diabetes prevalence from 382 million in 2013 to 592 million by 2035.[1] According to another study, it has been projected that the number of diabetes patients will rise to 693 million by 2045 from 451 million in 2017.[2] It is also estimated that 49.7% of people living with type II diabetes are undiagnosed. In developing countries, the majority of diabetes patients are younger than 64 years, and diabetes in the adult population is expected to increase by 69% from 2010 to 2030 in developing countries as compared to 20% for developed countries.[3]
The management of diabetes often requires insulin administration, which is a potent and cost-effective substitute for oral hypoglycemic agents to attain normoglycemia. It is generally started 10 to 15 years later, but insulin therapy at the early stages of diabetes has proven to be a better agent for prolonged glycemic remission.[4] Insulin can be delivered through various devices, including traditional vials and syringes (VaS) system and prefilled pens. The choice between these options can significantly impact patients' experience, adherence, and overall outcomes. While insulin syringes have been the conventional method, requiring users to draw insulin from a vial, advancements in technology have made prefilled insulin pens increasingly popular due to their ease of use, convenience, and accurate dosing. Insulin pens or pumps offer solutions to some disadvantages for individuals who find syringes problematic.[5] Prefilled pens offer a more user-friendly alternative, potentially enhancing adherence to insulin therapy by reducing the burden associated with daily injections. Understanding the usability and patient preference for these devices is critical for optimizing diabetes management and improving patient quality of life (QoL).
In Pakistan, diabetes has become a significant public health challenge, with a rapidly rising prevalence due to factors such as urbanization, sedentary lifestyles, and dietary changes.[6] Insulin therapy is a cornerstone in the management of type I and advanced type II diabetes. Yet, its administration remains a barrier for many patients, often due to a lack of access to user-friendly devices and educational resources. Insulin syringes are commonly used because they are relatively affordable and widely available. However, the manual process of drawing insulin from a vial can be daunting, particularly for patients with limited health literacy, physical disabilities, or those living in rural areas with minimal health care support. Consequently, adherence to insulin therapy may be suboptimal, leading to poor glycemic control and an increased risk of diabetes-related complications.
In recent years, prefilled insulin pens have emerged in the Pakistani market as an alternative to traditional syringes, offering potential advantages such as ease of use, convenience, and more precise dosing.[5] However, these devices are often more expensive, which can be a barrier to widespread adoption in a country where a significant portion of the population has limited financial means. Additionally, cultural factors, including patient perceptions of technology and the role of health care providers in influencing treatment choices, play a role in the acceptance of new insulin delivery methods. So, this study aimed to assess the usability and patient preference for insulin syringes versus prefilled pens in Pakistan, taking into account local socioeconomic, cultural, and health care system factors.
Methodology
A prospective cross-sectional investigation was conducted at Polyclinic Hospital in Islamabad over 6 months from February to June 2024. Ethical approval for the study was obtained from the institutional ethical review board of Quaid-i-Azam University and Federal Government Polyclinic Hospital, ensuring adherence to ethical standards in research conduct. The research was carried out in various wards, including the medical, orthopaedic, intensive care unit (ICU), medical ICU, and urology ward, as well as outdoor patients to capture a diverse patient population who were either self-administering insulin or receiving assistance from family members in terms of insulin administration.
The inclusion criteria targeted patients with type I or type II diabetes from both genders who used insulin at home via self-injection or with help from family members. Patients on insulin therapy during hospitalization were excluded if they received injections only from health care professionals, had a language barrier, or were those who did not consent or manage their diabetes solely with oral hypoglycemic agents. Using a convenient sampling method, data were collected from 50 patients. Data confidentiality and anonymity were maintained throughout the study.
The study included two sections of a well-structured adapted questionnaire[7] that was used to collect data targeting traditional VaS system and insulin pen users. There were three components in each section. In both sections, the first two components were identical. Thirteen general questions on the patient's demographics, diabetes type, length of insulin use, fasting blood glucose and HbA1c monitoring, concurrent use of oral hypoglycemics, and other comorbidities made up the first component. Nine questions that outlined the administration methods were included in the second component. Either insulin pen users or traditional VaS users were the focus of the final component.
The administration method included questions about the awareness of each technique in terms of proper storage (in the fridge before opening and at room temperature or fridge after opening), angle of administration (answered as 45 or 90 degrees as a correct method according to the body mass index), examining the suspension before use, the process of shaking (rubbing as a proper method), cleaning the site of administration, rotating the site of injection (rotating within the same region for morning dose and another region for evening dose or rotating between sites from one injection to another), releasing trapped air from the vial/syringe (for conventional device) or hearing the click (for pen), using a new needle for every injection and throwing away needles directly after injection. The responses were converted to either “incorrect” (0) or “correct” (1). “Safety and simplicity” included information about pain perception, bruises, hypoglycemia, ease of use, and comfort on using a device for which answers were converted to either “0” as a more negative impact or “1” as a less negative impact on patients.
The primary endpoints included the safety, simplicity, patient preference, and convenience of insulin administration. Safety considerations covered pain, hypoglycemic episodes, and bruising at injection sites. Simplicity was assessed through questions on ease of use and comfort using a device (pen/VaS) without guidance. Patient preferences and convenience were gauged by asking pen users about the ease of shifting to the pen and VaS users if they would switch to a pen if it were equally priced. The secondary endpoint was the awareness of the method of administration as mentioned earlier.
The collected data were analyzed using SPSS version 26, employing descriptive statistics and one-way analysis of variance (ANOVA) tests, t-tests, and logistic regression analysis. A p-value of ≤0.05 was considered statistically significant in evaluating the results.
Results
In this study, 52 patients were surveyed, of whom 29 (56%) were VaS users, while the remaining patients (44%) used an insulin pen. [Table 1] compares the respondents' demographic, clinical, and treatment characteristics. VaS users predominantly have type II diabetes (79%), while type I diabetes was more common among pen users (65%). Age distribution showed a higher proportion of older individuals (>58 years) in the VaS group (59%). Body mass index (BMI) indicated a higher prevalence of obesity in pen users (35%). Insulin use was similar, with most requiring 10 to 20 units daily and using it for 1 to 5 years. Combination oral hypoglycemic therapy was more common in VaS users (83%). HbA1c monitoring every 3 months was frequent in both groups, while comorbidities like hypertension (41%) and renal disease (41%) were more prevalent in VaS users.
Table 1
Demographic and clinical characteristics of respondents (n = 52)
|
Variables
|
VaS user, N (%)
|
Pen user, N (%)
|
|
Female
|
16 (55)
|
13 (57)
|
|
Male
|
13 (45)
|
10 (43)
|
|
Age (y)
|
|
18.0–28.0
|
10 (34)
|
12 (52)
|
|
28.1–38.0
|
15 (52)
|
13 (57)
|
|
38.1–48.0
|
13 (45)
|
09 (39)
|
|
48.1–58.0
|
16 (55)
|
14 (61)
|
|
>58
|
17 (59)
|
09 (39)
|
|
BMI
|
|
Normal
|
12 (41)
|
07 (30)
|
|
Overweight
|
10 (34)
|
08 (35)
|
|
Obese
|
07 (24)
|
08 (35)
|
|
Diabetes type
|
|
Type 1
|
06 (21)
|
15 (65)
|
|
Type 2
|
23 (79)
|
08 (35)
|
|
Diabetes duration (y)
|
|
1–5
|
12 (41)
|
07 (30)
|
|
6–10
|
10 (34)
|
10 (43)
|
|
11–20
|
05 (17)
|
04 (17)
|
|
>20
|
02 (7)
|
02 (9)
|
|
Insulin use duration (y)
|
|
1–5
|
16 (55)
|
12 (52)
|
|
6–10
|
09 (31)
|
08 (35)
|
|
11–20
|
04 (14)
|
03 (13)
|
|
>20
|
02 (7)
|
01 (4)
|
|
Insulin units per day
|
|
10–20
|
14 (48)
|
10 (43)
|
|
21–30
|
09 (31)
|
08 (35)
|
|
31–40
|
04 (14)
|
02 (9)
|
|
41–50
|
03 (10)
|
02 (9)
|
|
>50
|
02 (7)
|
01 (4)
|
|
Oral hypoglycemic
|
|
Single drug
|
05 (17)
|
10 (43)
|
|
Combination therapy
|
24 (83)
|
13 (57)
|
|
Insulin injection frequency per day
|
|
Once
|
14 (48)
|
10 (43)
|
|
Twice
|
11 (38)
|
13 (57)
|
|
Other
|
04 (14)
|
01 (4)
|
|
HbA1c monitoring frequency
|
|
Every 3 mo
|
18 (62)
|
15 (65)
|
|
Every 6 mo
|
07 (24)
|
06 (26)
|
|
>6 mo
|
04 (14)
|
02 (9)
|
|
Comorbidities
|
|
Heart failure
|
03 (10)
|
02 (9)
|
|
Dyslipidemia
|
11 (38)
|
08 (35)
|
|
Stroke
|
02 (7)
|
01 (4)
|
|
Hypertension
|
12 (41)
|
06 (26)
|
|
Glaucoma
|
07 (24)
|
08 (35)
|
|
Renal disease
|
12 (41)
|
09 (39)
|
|
No comorbidity
|
05 (17)
|
04 (17)
|
Abbreviations: BMI, body mass index; VaS, vial and syringe system.
Safety and simplicity domains were classified, including the following five factors: pain, hypoglycemic episodes, bruising at injection sites, ease of use, and comfort using a device (pen/VaS) without guidance ([Table 2]). Pain perception is a major barrier to accepting insulin therapy. A statistically significant higher percentage (78%) of pen users reported no pain during injection compared to only 31% of the conventional users. No statistically significant difference was seen between the groups in the incidence of hypoglycemia. Another safety outcome addressed in our study was the percentage of bruises at the administration site. More patients among the conventional users developed bruises at the site of administration (55%) compared to 43% of the pen users but with no significant levels (p = 0.154). As for reading the scale, 76% of VaS users could read the scale easily versus 57% of pen users (p = 0.045). When asked how comfortable they would feel using a syringe or a pen without a guide, 61% of insulin pen users answered they were “comfortable” and “very comfortable.” Moving to another primary endpoint, which studied patients' preference and convenience, 78% of pen users found it more convenient when shifting to a pen. However, only 69% of conventional users would want to shift to the pen if it were the same cost as the traditional VaS system.
Table 2
Percentage of safety and simplicity variables
|
Safety and simplicity variables
|
VaS user (%)
|
Pen user (%)
|
|
Pain
|
|
Yes
|
69
|
22
|
|
No
|
31
|
78[a]
|
|
Hypoglycemic episodes
|
|
1 in 3 mo
|
10
|
09
|
|
>1 in 3 mo
|
03
|
00
|
|
Bruising
|
|
Yes
|
55
|
43
|
|
No
|
45
|
57
|
|
Ease of use
|
|
Easy
|
76[a]
|
57
|
|
Intermediate
|
17
|
30
|
|
Hard
|
07
|
13
|
|
Comfortable using the device
|
|
Very uncomfortable
|
21
|
17
|
|
Uncomfortable
|
17
|
22
|
|
Comfortable
|
48
|
52
|
|
Very comfortable
|
14
|
09
|
Abbreviation: VaS, vial and syringe system.
a Significant at p ≤ 0.05.
The percentages of correctness for all administration procedures are calculated in [Table 3], and a t-test was conducted to test the significant level of difference in administration procedures between pen and traditional VaS users. Pen users, as compared to conventional users, had a significantly lower percentage of correctness on shaking (18 vs. 55%), on examining the suspension (40 vs. 52%), and on changing the needle on every attempt (0 vs. 12%). Surprisingly none of the users in either category practice throwing needles after the injection.
Table 3
Percentage of correct administration procedures
|
Administration procedure
|
VaS user (%)
|
Pen user (%)
|
p-value
|
|
Storage
|
100
|
95
|
1.0
|
|
Angle of administration
|
38
|
40
|
0.18
|
|
Examining the suspension before use
|
52
|
40
|
0.22
|
|
Shaking before use
|
55
|
18
|
0.013[a]
|
|
Cleaning the site of administration
|
24
|
30
|
0.31
|
|
Rotating the site of injection
|
40
|
55
|
0.07
|
|
Releasing trapped air from the vial/syringe (for conventional device) or hearing the click (for pen)
|
65
|
57
|
0.05[a]
|
|
Using a new needle for every injection
|
12
|
0
|
0.05
|
|
Throwing away needles directly after injection
|
0
|
0
|
–
|
Abbreviation: VaS, vial and syringe system.
a Significant at p ≤ 0.05.
A logistic regression, as shown in [Table 4], was conducted to test how the safety and simplicity variables, together with administration factors, influence diabetic patients' preference for the VaS system over insulin pens. Surprisingly, the results showed that pain was the only significant parameter that influenced the decision in the category of safety, whereas no administration procedure was a significant factor at the 5% level.
Table 4
Logistic regression analysis of safety, simplicity, and administration variables in the study population
|
Variables
|
Coefficient
|
Standard error
|
p-value
|
|
Pain
|
3.51
|
0.56
|
0.004[a]
|
|
Hypoglycemic episodes
|
−2.20
|
0.029
|
0.12
|
|
Bruising
|
0.97
|
1.10
|
1.94
|
|
Ease of use
|
5.23
|
2.38
|
0.12
|
|
Storage
|
−26.12
|
1.42
|
0.957
|
|
Angle of administration
|
−0.38
|
0.029
|
0.380
|
|
Examining the suspension before use
|
−0.91
|
2.23
|
0.086
|
|
Shaking before use
|
12.6
|
2.38
|
0.51
|
|
Cleaning the site of administration
|
−38.42
|
5.85
|
0.99
|
|
Rotating the site of injection
|
4.20
|
0.39
|
0.176
|
|
Releasing trapped air from the vial/syringe (for conventional device) or hearing the click (for pen)
|
−0.91
|
1.53
|
0.278
|
|
Using a new needle for every injection
|
−0.53
|
1.52
|
0.744
|
|
Throwing away needles directly after injection
|
−15.03
|
3.35
|
1.0
|
a Significant at p ≤ 0.05.
Discussion
Diabetes is a chronic disease that impacts patients' lives a lot, and thus, patients need special attention and care in order to manage their lives through frequent glucose monitoring, daily monitoring of carbohydrate intake, and lifestyle modifications.[1] Insulin therapy is made more difficult for patients by a number of social and financial obstacles they must overcome before starting it. This study provides valuable insights into the usability and patient preferences for insulin delivery methods among a cohort of diabetic patients in Pakistan, revealing critical factors that influence the choice and satisfaction with these devices. The findings indicate that prefilled insulin pens are generally perceived as more user-friendly, offering convenience and ease of use, especially for patients with limited dexterity or visual impairments. The results parallel those of Korytkowski et al in which 74% of patients indicated a preference for the pen over the VaS system, compared with 20% who preferred the VaS system.[8] It was also researched that 74% considered the pen easier to use overall, compared with 21% for the VaS system, and 85% of insulin pen users found reading the scale easy to use compared to only 10% of the conventional users who believe that reading the scale is easy to read.[7]
Insulin pens are perceived as less painful when compared to a conventional VaS system. In fact, needle phobia has been studied in many clinical trials. A study about the needle gauge and its association with pain was conducted on 30 healthy volunteers; 40.3% reported that a large size needle was significantly more likely to cause pain compared with a lesser outer diameter needle.[9] Another open-label, crossover study comparing patient preference and pain perception between different insulin pens showed that the pen with a 33-gauge lubricant-coated needle had a significantly superior (p < 0.001) overall patient satisfaction score with less fear and less bleeding tendency.[10] These attributes align with global trends showing that user-friendly devices enhance adherence to insulin therapy. However, the higher cost of prefilled pens compared to traditional syringes emerged as a significant barrier, particularly in a resource-constrained setting like Pakistan, where affordability often dictates health care choices.
The results of this study dictate a need for insulin technique awareness for the diabetic population of Islamabad. The majority of patients under study did not clean the site of injection before injecting insulin, did not rotate the site of administration, did not use a new needle for every injection, and did not throw away the needle directly after injections. However, those are the key factors for proper insulin administration in order to avoid infections. Patients should be instructed on the correct injection depth, site, and technique. Insulin depth should be sufficient to avoid intramuscular injections that lead to rapid absorption and a higher risk of hypoglycemia.[9]
[11]
This study has several potential limitations. First, using a convenient sampling method may limit the generalizability of the findings to the broader diabetic population in Pakistan. Additionally, the reliance on self-reported data for preferences and convenience introduces the possibility of recall bias. The study's cross-sectional design captures patient experiences at a single point in time, which may not reflect long-term usability or adherence outcomes. Finally, since the survey was conducted in a single health care setting targeting only a specific number of patients, the findings may not fully represent patients in other regions or health care environments across Pakistan.
Future studies could incorporate objective measures such as continuous glucose monitoring (CGM) or glucometer records to minimize bias to validate episodes. Limiting recall periods to recent events (e.g., 2 weeks) and using standardized definitions of hypoglycemia can improve the consistency and accuracy of patient responses. Structured and validated questionnaires and training interviewers to avoid leading questions can further reduce recall and interviewer bias. Cross-verifying patient reports with caregivers or medical records and ensuring participants are not overly focused on the study's primary objective can minimize response bias.
Conclusion
This study highlights important insights into the usability and patient preferences for insulin delivery methods among diabetic patients in Pakistan. Prefilled insulin pens were generally favored for their ease of use, convenience, and potential to improve adherence. At the same time, traditional VaS systems were more commonly used due to affordability and accessibility. The findings suggest that while prefilled pens may enhance patient satisfaction and simplify insulin administration, economic and systemic barriers remain significant factors influencing their adoption. Patients in both groups need more awareness about the method of administration, aseptic injection techniques, and proper disposal of needles/syringes. Understanding these factors is crucial for optimizing diabetes treatment strategies and enhancing patient satisfaction and adherence. Future research directions include investigating long-term adherence rates and clinical outcomes associated with different insulin delivery methods, which could further inform clinical practice and improve diabetes care protocols in the whole country. Studies on larger and more diverse populations are also recommended to validate these findings and explore long-term outcomes of device preferences on glycemic control and QoL.
