Study setting
The SANITHY (SAfety Needles and Insulin pens at Treviglio Hospital – ItalY) study is a pilot study designed to implement the use of insulin pens in the hospital setting at the Treviglio General Hospital, northern Italy. From October to the end of December 2012, consecutive patients requiring multi-injection insulin therapy and admitted to three hospital units of different intensity of care (Cardiology and Coronary Care Unit; Neurology and Stroke Unit; Medicine and Urgency Unit) received the traditional vial and syringe method. Insulin pens and safety needles were adopted in the same hospital units the next successive three months from January to the end of March 2013 in consecutive patients requiring insulin therapy. The following insulin and prefilled insulin pens were utilized: Humalog© and Humalog Kwikpen© (Eli Lilly and Company, Indianapolis, USA) as rapid acting insulin; Lantus© and Lantus SoloSTAR© (Sanofi, Paris, France) as long-acting basal insulin. Together with pen devices, pen needles with a dual-ended protection safety system Autoshield Duo© (Becton, Dickinson and Company, Franklin Lakes, NJ, USA) were utilized. The dual-ended protection covers both the portion of the needle in contact with the patient, and the back-end which penetrates into the rubber tip of the pen. Prior to the study, nurses received a specific training program on insulin pens consisting of small-group sessions and hands-on training, with individual testing to insure competence in using the insulin pen devices and safety needles properly. Thereafter, study nurses administered prescribed insulin therapy with pens and safety needles to inpatients, under an expert’s supervision, to demonstrate the acquired technical skill. Moreover, slides and a short explicative movie were available on our hospital Local Area Network portal (e-learning) and a 24 h, 7 day a week, toll-free phone number was active during the study period to interact with expert consultants. The pilot study was approved by the Independent Ethical Committee of the Treviglio Hospital.
The nursing satisfaction survey questionnaire
The Nursing Satisfaction Survey Questionnaire (NSSQ) was proposed by Davis et al. to evaluate nurse satisfaction using pen devices as compared to vials/syringes in a sample of US nurses [8], in a study setting very similar to ours. The first section of the NSSQ collects information on the number of years practiced as a nurse, as well as on the previous experience with insulin administration and with study pen devices. Nurses’ satisfaction with insulin pen devices as compared to vial/syringes is then investigated through 8 items, each on a 5-point Likert scale ranging from “strongly disagree” to “strongly agree”, addressing different aspects such as insulin preparation and administration, convenience and ease of use, confidence and comfort in insulin administration, and time spent in dose preparation and administration. Items are reported in Table 2. Finally, the questionnaire attempts to quantify the time spent by the nurses to teach study patients how to self-inject insulin with each device, categorized as “<5 min”, “<15 min”, “<30 min”, “<60 min”, “60+ min”. One question is dedicated to naïve insulin patients, and another one to experienced insulin patients. The Italian version of the questionnaire is available upon request to the corresponding author.
Study population and data collection
With the author’s permission, the NSSQ was translated to Italian and first administered to n = 44 nurses (questionnaire test sample) working in units not involved in the pilot study, but of the same Medical Sciences Department. The internal consistency was found to be satisfactory (Cronbach’s alpha = 0.91), thus, the questionnaire was administered to study nurses (n = 60, with characteristics comparable to the first group) at the end of the study period. The responses to the questionnaire were anonymous and completed independently.
Statistical analysis
Study sample characteristics were summarized using standard statistics including mean, standard deviation and proportions. Responses to each of the 8 items assessing satisfaction with pen devices compared to vial/syringes were attributed a score ranging from 1 (“strongly disagree”) to 5 (“strongly agree”); the sum of the item responses could range between 8 and 40. We reported the mean score and standard deviation for each item, as well as the prevalence of a positive response defined as “agree” or “strongly agree”, as suggested by the authors [8]; and tested the null hypothesis of prevalence of positive answer equal to 50 % (i.e., no preference) using a two-sided exact binomial proportion test. To identify the latent structure of nurses’ satisfaction, we performed an exploratory factor analysis, given that the original NSSQ was not validated. The Kaiser-Meyer-Olkin measure of sampling adequacy value of 0.85 and the Bartlett test of sphericity (p-value: <.0001) supported the use of factor analysis. We fixed in 80 % the minimum proportion of cumulative variance to be explained by the factors as a general rule to decide the factors number; a scree plot was also used. Since the analysis made on the questionnaire test sample revealed a strong correlation between the 8 items, we considered an oblique factor rotation (promax), to allow for a non-zero correlation between the factors [12]. Internal validation for each retained factor was assessed through Cronbach’s alpha [13]. Finally, we assessed the relationship between each retained factor and time spent to teach patients how to self-inject insulin with pen devices. We reported the median (25°–75° percentile) of each factor score (as the sum of the responses to the items included in the factor) by categories of time, and formally tested the null hypothesis of no difference in factors score by time through a Kruskal-Wallis non parametric test [14]. All the statistical analyses were performed using the SAS software, version 9.3.2.