I have data from groups of professionals with in the same medical field. They are grouped according to years in practice. Each group going up in 5 year increments.ie 0-5 yrs experience 6-11 etc. Individually all were asked a set of questions from which I was only interested in one response based on my hypothesis. I'm wanting to see, if the more experienced in practice an individual is, the better they are at spotting a disease. What is the best statistical test to use when comparing the nine age groupings against each other in relation to the frequency each group has for the 1 question I zoomed in on?
I would set up an ANOVA test, grouping the individuals by whether they got your question right or wrong. Your null hypothesis is that the means of the years of experience between the two groups is not significantly different. Then you can answer the question "Do the people that answer the question right tend to have more years experience?".
You could use a logistic regression on the years of experience and see whether the resulting coefficient is significantly different from zero.
I agree with @NickAdams that you should definitely not discretize your continuous years-of-experience variable. This is very bad practice. See, e.g., here ("Much is lost and nothing gained by a median split.") or here or here. Everything that is bad about dichotomizing continuous variables also applies to splitting continuous variables into more than two bins.