The unifying theme of successful nursing research proposals is that the author(s) observed a problem, did research to make sure the observation was not personal bias, and then wrote to describe not only the problem, but a potential solution. Elsevier maintains a list of nursing proposal abstracts on its website.
One example of a nursing research proposal from Elsevier's website is "Factors associated with falls in hospitalized adult patients." This is a longitudinal survey of the factors that cause falls in adults and provides recommendations on how to mitigate the circumstances of those falls. Another proposal is "Effects of exercise programs on depressive symptoms, quality of life, and self-esteem in older people." This study looks at regular exercise to see if it can help the elderly cope with depressive issues.
"Social support needs of families: The context of rheumatoid arthritis" is an examination of the impact caring for an arthritis sufferer has on his family and what the medical profession can do to help further. Another example on Elsevier's website is "Recognizing global disparities in health and in health transitions in the 21st century: What can nurses do?" This sweeping proposal attempts to examine the differences in medical care, of quality and availability, between first- and third-world countries and asks what can be done about it.