I would strongly suggest that you create a foreign key table to maintain this and use a join query to get the value.
If you can't or don't want to use this approach then you would need to use a case statement
WHEN 0 THEN 'Incomplete'
WHEN 1 THEN 'Complete'
ELSE 'Unknown Value'
If you use this approach I would suggest that you make it a function - it would be slower but you would only need to maintain it in one place