This is a very ambitious scoping project looking for associations between antiinfective drug prescribing and measures of progression or amelioration across a range of neurological conditions. The requestors have asked for datasets from a range of trials. The validity of their findings will depend critically on the availability of detailed prescribing information and on the use of statistical analysis which can cope with great heterogeneity in outcome measures. I think the Data Holder will need to ensure that such information is uniformly available. Anti-infective drugs are usually prescribed over short periods of time varying from a single dose to a week or two. I am rather doubtful whether this information is consistently available in all the trials requested.