A couple of the function parameters are undefined:
unique - determines whether you want to return just unique indexes or all indexes. Use SQL_INDEX_UNIQUE or SQL_INDEX_ALL for this parameter
accuracy - whether you wan to return everything there is to know about the table or just what information is readily available. Use SQL_ENSURE or SQL_QUICK for this parameter
For a bit more info about this function see the ODBC function SQLStatistics() at http://msdn.microsoft.com/en-us/library/ms711022(v=vs.85).aspx