ID	Date	Description	Comment	Status	Next Step
1	6/12/2025	Convert bmi "N/A" to null	1. Presence of "N/A" in bmi caused an error in importing the data in the database. 2. Used Excel to find and replace all N/A to null.	complete	Identify, document, and handle null/missing values
2	6/13/2025	Investigate missing data	Found 201 null values in the bmi column.	complete	Investigate bmi column to determine appropriate action for null values.
3	6/13/2025	Filter out 65 and over	Based on study focus, patient records aged 65 and above were filtered out.	complete	Continue work with filtered dataset.
4	6/13/2025	Standardize text fields	Lowercase and trimmed gender, ever_married, work_type, residence_type, and smoking_status columns.	complete	Check categorical columns for uniqueness
5	6/13/2025	Distinct categories check	Checked distinct categories for each categorical column and verified that the categories are correct and unique.	complete	Remove duplicate rows excluding id
6	6/13/2025	Remove 'other' gender category	One instance of 'other' gender category was removed to eliminate potential noise in the dataset.	complete
7	6/13/2025	Remove duplicate rows	No duplicate rows found (id excluded).	complete	Proceed to EDA with feature engineering.