Sunday 17/03/07

I read through the Royal College of Pathologists Workload Guidelines again trying to pick out data fields that contribute to the workload and that are already captured on the lab system. I decided that there are 7 data items currently held in the lab system WinPath that the RCPath Workload Guidelines state are factors contributing to the overall workload of the pathologist. These are:

1. Specimen Type e.g. Breast Biopsy, Skin Biopsy etc. Approx 250 different types.
2. Levels - Are stains at various levels through the tissue block required. The more slides cut the longer it takes to examine them all.
   
3. Number of Special Stains Requested
4. Number of Immunocytochemistry Slides
5. 2nd Pathologists Opinion Required - Usually suspected cancer cases
6. Minimum Dataset Completed
   
7. Presentation at Multi Disciplinary Team Meeting

There are other data items recorded on the lab system which, although not specifically mentioned in the RCPath guidelines, do contribute to the overall complexity of the case and therefore the workload of the pathologist. These are:

1. Number of Specimens - Each case may consist of more that one specimen. The greater the number of specimens the greater the workload. The workload could be measured per specimen but the RCPath Guidelines suggest a workload per case with each specimen contributing to the overall score. I have chosen just to use the most major specimen type for each case as this has the greatest contribution to the overall work required to report the case. I will add some new specimen types to help deal with cases where we get multiple pots with a low complexity but because of their number this makes them more time consuming.
2. Number of blocks - Generally the number of blocks represents the amount of sampling the specimen(s) require. Complex cases usually require greater numbers of blocks to be taken. Each block produces a minimum of one slide for the pathologist to examine.
3. Extra H&E slides - A pathologist may request further levels on a block if the case is difficult to report.

There one data item mentioned in the guidelines that are not captured reliably by the lab system - usually due to user error - so I have developed a proforma to print on the back of the lab request forms to capture this acurately.

• Pathologist/BMS Cut Up - Simple cases are often described and sampled by BMS staff and are only microscopically examined by the pathologist.

Finally the workload for each case is classified on a scale of 1 to 10 with 1 being the least workload and 10 the highest. This is currently not assigned.

I aim to get the pathologists to assign the workload to their cases following the RC Path guidelines. Then extract the all the data from the lab system and add the supplementary data field to each case (Pathologist/BMS Cut Up?) Process the data to a form acceptable to a NN. Train the network with the data including the workweight assigned by the pathologist, then test with data that doesn't include the assigned workweight and compare this to the workweight assigned by the pathologists. The lab number can be used to compare the workweight from the NN to those from the pathologist. I would use a NN with 11 input neurons for the 11 data items and 10 output neurons for each workweight.

Problems:

• RCPath Guidelines, for want of a better description, are very woolly. I think a NN due to their black box nature can cope with the lack of clarity in the guidelines. However a KBS needs rules to be able to classify each case, and rules are difficult to create from this data. Handling uncertainty - fuzzy logic etc - is one way to cope with this but I think writing the rules in the first place would be difficult. I would probably have to analyse all the data and assign average scores to each data item - possibly, maybe. I think a KBS might be useful to preprocess the specimen type data before passing it to the NN.
• Bias - I think the Pathologist will over score the workload. They are not going to admit to being anything other than overworked
• Other factors that add to the pathologsits workload that aren't measured - e.g. Training of Junior Staff.