how to access MySQL OUT variable through PHP mysqli without result set

Is it possible to access an OUT variable from an SP called through mysqli without returning it via SELECT one way or another? I had a good look and tried the code here but it always needs a result set called within or after the SP to work.

Consider this code:

SQL:

DELIMITER $

# DROP PROCEDURE IF EXISTS outVar$

CREATE PROCEDURE outVar(OUT myVar TINYINT(1))
BEGIN

    SET myVar = 1;

END$

DELIMITER ;

CALL outVar(@myVar);

SELECT @myVar;

PHP:

 <?php

    $Conn = new mysqli("127.0.0.1", "root", "123456789", "test");

    $RResult = $Conn->query("CALL outVar(@myVar);");

    print_r($RResult->fetch_assoc());
?>

This returns the following:

Fatal error: Call to a member function fetch_assoc() on boolean in C:\xampp\htdocs\phpTest.php on line 7

Because there are no results returned in tabular form, fair enough. So am I correct in assuming that while OUT is elegant within mysql it's of no use in the mysqli context without the help of a result set leaving OUT redundant in this context? If not I'd love to know how to do it.

Thanks,

James