As a community health nurse I use all of these dimensions and they are all intertwined. The nursing process in community health is assessment, diagnosis, planning, implementation and evaluation. The assessment aspect is assessing a population or aggregate population and all of the facets of the community in which people interact (history, demographics, ethnicity, values and belifs, physical environment, health and social services, economy, transportation, safety (police, fire, EMS, crime rates), politics, government structure, communication (how do people communicate and get news, education (levels, schools), recreation (leisure activities, exercise). An important compenent in assessing a community is speaking with the residents to find out what they perceive their needs are. For example, after doing a community assessment on a small community where I live one thing that I found that the crime rate was high and that people were fearful of being burglarized. So, one of the community diagnosis was, "Stress and anxiety of being criminally burglarized related to increased episodes of thefts and burglaries as evidenced by police crime statistics of past four years and personal testimony of residents, especially the elderly." My plan was to increase street and business lighting as well as offer a public awareness program on home and personal security. This requires leadership and working with the local government and police to implement the plan (politics) It also helps if you learn how to write grants
. Once they were convinced of the need, it was implemented (not this simple, but you get the point). The local sheriff department helped with home visits of elderly folks to identify security issues in the home. Also, they helped with personal and property safety workshops (health education). We also enlisted volunteers from the fire department to help the elderly install additional safety devices in their homes. So, after the plans are implemented the community health nurse goes back after a time and evaluates whether or not the interventions decreased the crime rate and assessed the concerns of the people related to this issue.
The epidemiological dimension is identify incidence and prevalence of specific illness/disease/adverse events and attempt to find a causal relationship. Once you establish a causal relationship and risk factors, preventive and public programs can be developed to educate the public and/or takes steps to prevent occurences. One example of this is the American Academy of Pediatrics public awareness campaign of "Back to sleep" for infants to decrease the incidence of SIDS. Infant sleep position is not the only risk factor for SIDS, but this campaign made an impact in the incidence and prevalence of this tragic event. It was epidemiology that did (and still is) identifying risk factors for SIDS. These are just some small examples, hope this helps. Sorry for such a long post.