It found that communication with nurses, pain management, communication about medication, responsiveness of the hospital staff, and the overall rating of the hospital were consistently clustered together, and that communication with nurses leads the way.
Translation? Efforts to improve scores in the area of communication with nurses will likely lead to higher scores in the other dimensions within that cluster, too. It's for this reason that the study calls nurse communication a "rising tide measure;" something for hospitals to focus on and improve that will set off a chain reaction of improvements in multiple areas.
This study uses appropriately rigorous methodology, but really, connecting the dots on these quality measures is just common sense.
Think about it. Nurses ask patients to rate their pain and are the ones who keep the pain meds coming, so it makes sense that quality measures connected with pain management and communication about medicines would be associated with nursing quality.
Also, when patients need help, nurses are the ones who answer their calls and pages with a visit to the bedside. Therefore, having nurses who are very responsive to those requests will likely help improve the "responsiveness of hospital staff" measure, too.
Plus, among all hospital staff they encounter, patients interact most frequently and regularly with nurses. Surely the quality of those nurse interactions color patients' overall perception of their hospital experience.
Research has consistently shown that nursing quality influences quality of care across wide measures of quality, and better nurses result in better quality.