Incorrect patient weights are a perennial patient safety problem. A new safety bulletin recommends acute care providers weigh all patients on admission (including upon arrival in the emergency room) and when the patient’s condition changes in a way that could affect weight, such as during cancer treatment, or simply over time, as with children. Providers should also use metric units rather than pounds for weight to avoid misunderstandings and math errors that can lead to incorrect medication dosages. 

The recommendations were published last month by the state of Pennsylvania, which collects extensive data on patient safety events. A collection of tools and resources for working with accurate patient weight were published concurrently by the Pennsylvania Patient Safety Authority, an independent state agency charged with improving the safety of care. 

Nine years ago, the Authority published its first advisory linking inaccurate patient weight to medication errors, but the problem persists. Why? Contributing factors include:

• Lack of proper equipment for weighing non-ambulatory patients; lack of metric scales

• Patient record forms ⁠— digital or hard copy — not designed to record weight in grams and kilograms

• Clinicians’ overconfidence in their ability to accurately estimate weight or reliance on patient-reported weights