The example given in the endgame measures association between rates of trimethoprim prescription and trimethoprim-resistant bacteria in urine samples. Rates of trimethoprim prescription is measuring the data at practice level but measurement of trimethoprim-resistant bacteria in urine samples is at individual level. The unit of observation in the latter is individual level while in the former is practice level (or a group or cluster level or natural group level). What our humble submission is:
The unit of observation need not be individual level. It can jolly well be a group/population/ cluster level. For example: observing co-relation between environment pollution and mortality between metropolitan cities of a country where co-relation between both variables will be derived from the data at metros level.
Rapid Response:
Re: Understanding the ecological fallacy
The example given in the endgame measures association between rates of trimethoprim prescription and trimethoprim-resistant bacteria in urine samples. Rates of trimethoprim prescription is measuring the data at practice level but measurement of trimethoprim-resistant bacteria in urine samples is at individual level. The unit of observation in the latter is individual level while in the former is practice level (or a group or cluster level or natural group level). What our humble submission is:
The unit of observation need not be individual level. It can jolly well be a group/population/ cluster level. For example: observing co-relation between environment pollution and mortality between metropolitan cities of a country where co-relation between both variables will be derived from the data at metros level.
Competing interests: No competing interests