Analyzing the impact of subcutaneous injection needle, device, and administration characteristics on patient pain, anxiety, and safety: a systematic literature review.
The subcutaneous (SC) injection route is a commonly used and important method for therapeutic delivery of a wide range of compounds, and needle characteristics have a significant influence on patient pain, anxiety, safety, and other outcomes. This systematic review evaluates the evidence on how needle-specific characteristics (e.g. gauge, length, tip design, wall thickness, concealment) and administration- or device-related factors can affect patient-reported outcomes and clinical safety indicators during and following SC injections. A comprehensive search was conducted in MEDLINE, PubMed, Embase, and ClinicalTrials.gov in June 2024. Studies were included if they assessed the relationship between needle characteristics and pain, anxiety, safety, or related outcomes in individuals receiving SC injections. A dual-reviewer process was used for study selection, data extraction, and quality assessment. Sixty-two studies met inclusion criteria. Evidence consistently indicated that thinner and shorter needles reduced patient-reported pain and adverse events such as bruising and bleeding. Tapered and lubricated needles, hidden or retractable needle designs, and use of autoinjectors or prefilled syringes also contributed to reduced anxiety and improved user satisfaction. However, results were heterogeneous, and many studies lacked sufficient power or single-variable evaluation of individual needle parameters, limiting definitive conclusions. Needle characteristics significantly influence patient experience and safety with SC delivery. While both clinical evidence and practical experience clearly favor thinner, shorter, and concealed needles, further standardized, high-quality research is needed to isolate and quantify the specific contributions of individual needle characteristics to optimize injection practices and support patient-centered device design.