Medical records can help prevent disease and improve treatment—even when parts of a patient’s story are missing. But the way those blank spaces are handled can quietly change the conclusion doctors and researchers reach. Electronic health records are widely accepted to enhance health care quality, patient monitoring, and the early prevention of various diseases, even when information in them is incomplete or missing.

That makes them valuable not only for treating illness, but also for noticing risks earlier and following patients over time. The review investigates how using electronic health records affects health care quality and medical decisions when information is missing or incomplete.

The central question is simple: how much can a medical conclusion be trusted when the record does not contain the whole story? The review presents the challenges of using electronic health records for population health investigations when information is missing. It also discusses the common ways researchers handle missing information so they can reach valid conclusions.

The reviewed studies use many different approaches to manage missing information. Some keep only records with complete information, while others fill gaps using averages or more advanced approaches for certain kinds of measurements.

One approach keeps only records with complete information, while another uses stratified mean imputation; more advanced methods can interpolate some longitudinal measurements. Few studies used informative observations, where the fact that a measurement is present can itself carry meaning about a value that is missing.

One method using deep learning reduced errors caused by filling in missing values under different situations, compared with four other techniques, and could help physicians and researchers use patient records for better management. The review finds that electronic health records are an increasingly important tool for health professionals and decision makers.

They can improve health care systems for patients and doctors by helping prevent and treat both long-term and other diseases. But the review cannot measure how well electronic health records perform in clinical practice because there is no well-established measure for doing so.

It therefore cannot quantitatively assess whether they save money when they guide medical decisions. The review highlights the importance of using electronic health records in clinical practice, while also pointing out a gap in knowledge about handling missing information.

For patients and doctors, electronic health records are increasingly important tools that can make health systems more convenient, improve health-care quality, and possibly save money. At the same time, the review highlights a continuing gap in knowledge about techniques for handling missing data in clinical practice.

Electronic health records can improve care, prevention, convenience, and costs, but this review finds no widely accepted way to deal with missing information. Better handling is needed before incomplete records can reliably guide decisions.