Hi there,
I'm currently in the process of carrying out a systematic review and I've gathered cost estimates from studies for a specific type of treatment (with two different approaches), I am interested in finding out if these costs have decreased over time.
I have 40 cost estimates for the one treatment approach and 12 cost estimates for the other treatment approach, spanning from 2012  2020. When I plot a simple scatter graph (y) Cost vs (x) Year, with a line of best fit I can see that Costs decrease as the Year increases for both approaches.
I was wondering is there any statistical test I can do to show that the costs are decreasing over time, I would like a test with a pvalue to 'prove' (or disprove) that there is a decreasing trend in costs over time. I do not want to do linear regression (because I only have 12 estimates for one of the approaches).
The costs for both approaches are significantly positively skewed, so I assume it would need to be a nonparametric test.
Thanks for your help!
I'm currently in the process of carrying out a systematic review and I've gathered cost estimates from studies for a specific type of treatment (with two different approaches), I am interested in finding out if these costs have decreased over time.
I have 40 cost estimates for the one treatment approach and 12 cost estimates for the other treatment approach, spanning from 2012  2020. When I plot a simple scatter graph (y) Cost vs (x) Year, with a line of best fit I can see that Costs decrease as the Year increases for both approaches.
I was wondering is there any statistical test I can do to show that the costs are decreasing over time, I would like a test with a pvalue to 'prove' (or disprove) that there is a decreasing trend in costs over time. I do not want to do linear regression (because I only have 12 estimates for one of the approaches).
The costs for both approaches are significantly positively skewed, so I assume it would need to be a nonparametric test.
Thanks for your help!
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