0

I am working with matched case-control data that used risk-set sampling with replacement (a control can be matched to more than one case). I am trying to figure out the correct syntax for conditional logistic regression with appropriate variance estimation.

This is the syntax I used for the unadjusted OR without cluster robust SEs:

clogit(case_status ~ exposed + strata(match_id), data = data_analysis) |>
  broom::tidy(exp=TRUE, conf.int=TRUE) 

# OR = 1.134 (95% CI: 0.898, 1.433) 
# Got same result with method="exact" (default) as other methods

This is the syntax I used to get cluster robust SEs to account for within-subject correlation. However, the robust SEs were smaller than the original SEs, which is the opposite of what I would expect.

clogit(case_status ~ exposed + strata(match_id), data = data_analysis, 
  method="breslow", cluster = subject_id) |>
  broom::tidy(exp=TRUE, conf.int=TRUE) 

# OR = 1.134 (95% CI: 0.931, 1.382) 
# method="exact" doesn't work with cluster option

Any help to understand why I may be getting smaller robust SEs or suggestions to modify my analysis would be greatly appreciated.

Thank you!

0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.