For pediatric hospital patients in need of fluids quickly, successfully inserting a peripheral intravenous catheter, commonly known as an IV, is often a medical necessity and critical first step in treatment. The process involves a hollow, metal needle that is beveled at one end and sheathed in a plastic catheter tube [1]. Once the needle has been successfully placed in the lumen, or interior, of the vein, the catheter is pushed over the end of needle. The metal component is then removed from the vein, leaving the catheter in place. This process is necessary to infuse needed fluids and/or medications into the body while preventing swelling in the patient.
The process of IV placement is unique in that there are very few alternatives to it, so in virtually all cases the process must be performed until it is successful. For pediatric patients, the procedure can be particularly difficult and time consuming. Factors such as patient age and unfamiliarity with the process present difficulties in pediatric IV placement. It is not uncommon for the process to require several separate needle stick attempts for a single patient.
Previous studies have been conducted to research the factors that impact successful IV insertion. Gorelick [2] studied 615 children aged 0-21 years who underwent peripheral intravenous catheter placement by staff nurses in a pediatric emergency department. Information on predictor variables was obtained before attempting intravenous placement, as well as whether the outcome was successful on the first attempt. Backward stepwise logistic regression was used to identify factors independently predictive of success. The study concluded that patients exhibiting prematurity, under the age of 1, or between the ages of 1 and 2, could be assessed different difficulty scores.
Larsen [3] and Goff [4] studied 592 children ages 0-18 who underwent pediatric IV catheter insertions in the inpatient setting at two southeastern US teaching hospitals. Larsen [3] sought to identify the predictive variables for successful IV insertion. The data was analyzed using a combination of a logistic regression model for success on first attempt, repeated measures logistic regression across multiple stick attempts, and a proportional hazards model on time to success. Larsen's results indicated that shift (day versus night), health professional perception of difficulty of the IV insertion, and the level of cooperation of the child all significantly contributed to the odds of a higher than usual number of IV attempts.
The published regression models for the Larsen study may not have fully utilized all aspects of the data. Specifically, none of the aforementioned models considered the data under the notion of a counting process. It is possible that other effects could be discerned with a second analysis of the data. The data were truncated into success/not success bins for either the first stick attempt or the general overall process. This truncation does not fully take into account the structure of the collected data as a multiple attempt process. Furthermore, it is unclear whether the use of count regression modeling provides superior results from traditional ordinary least squares regression modeling. The goal of this paper is to determine the appropriateness of a negative binomial assumption and to use a negative binomial regression model to take a second look at identifying factors which lead to successful IV placement.