| Value | Category | 
                                    
                    
                        | 0 |  | 
                                    
                    
                        | 1 | significantly improve | 
                                    
                    
                        | 2 | just improve | 
                                    
                    
                        | 3 | doesnot improve | 
                                    
                    
                        | 4 | difficult to answer | 
                            
            Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.