You could use an interface, I don't have a good grasp of whether an interface is better, or whether the current approach is better. I thought that the if statements that were added wouldn't be required if it were a 'pure' decorator. Something like:

```
new LoggingStatement(new Statement($pdoStatement));
```

Where LoggingStatement and Statement offer the same interface. This way if we needed to add more decorators later we could re-use the same pattern.  Most methods in Statement/LoggingStatement would just proxy to the decorated object.