*** Data underlying the publication: Test characteristics of Raman spectroscopy integrated with polarized light microscopy for the diagnosis of acute gouty arthritis ***
Authors: Tom Niessink
Medical Cell Biophysics group, University of Twente, Enschede, the Netherlands

Corresponding author: Tom Niessink

Contact information: t.niessink@utwente.nl

***General Introduction***
This dataset contains a full overview of 2015 ACR/EULAR gout classification scores and synovial fluid analysis of all patients included in the article Test characteristics of Raman spectroscopy integrated with polarized light microscopy for the diagnosis of acute gouty arthritis, DOI  https://doi.org/10.1016/j.jbspin.2023.105611

*** Methods ***
A full overview of the data gathering methods is given in the article. Patient data was retrieved from their electronic health records. Synovial fluid samples were collected prospectively in a consecutive series. Samples were analysed with both polarized light microscopy (by a rheumatologist) and a Hybriscan iRPolM integrated Raman polarized light microscope.

*** Data specific information ***
How to calculate the 2015 ACR/EULAR Gout score (Neogi et al. ARD 2015)								
Step 1. Entry criterion								
At least one episode of swelling, pain or tenderness in peripheral joint or bursa. All patients below fulfil this criterion								
Step 2. Sufficiency criterion								
Presence of MSU crystals in symptomatic joint, bursa or tophus. 								
Step 3. Criteria (to be used if step 2 is not met)								
A: Joint involvement								
Pattern of joint/bursa involvement during symptomatic episode(s) ever: 								
	1 pt	Ankle or midfoot (as part of monoarticular or oligoarticular episode without involvement of the first metatarsophalangeal joint)						
	2 pts	Involvement of the first metatarsophalangeal joint (as part of monoarticular or oligoarticular episode)						
B: Characteristics of episodes								
Presence of the following characteristics: erythemia of the skin around the joint; can't bear pressure or touch to affected joint; inability to use affected joint								
	1 pt	One characteristic						
	2 pts	Two characteristics						
	3 pts 	Three characteristics						
C: Time course								
Presence (ever) of >1, irrespective of treatment: time to maximal pain <24 hours; resolution of symptoms <15 days, complete resolution between symptomatic episodes								
	1 pt	One episodes						
	2 pts	Recurrent typical episodes						
D: Clinical evidence of tophus								
Draining or chalk-like subcutaneous nodule under transparent skin, often with overlying vascularity, located in typical locations: joints, ears, bursae, finger pads, tendons								
	4 pts	Present						
E: Laboratory 1								
Serum urate, highest ever measured								
	-4pts	=<0.24 mM						
	2 pts	0.36 - < 0.48 mM						
	3 pts 	0.48 - <0.60 mM						
	4 pts	=> 0.60 mM						
F: Laboratory 2								
Absence of MSU in synovial fluid when assessed by trained observer								
	-2 pts	If absent						
G: Imaging								
Imaging evidence of urate deposition: ultrasound evidence of double contour sign	

A:G are columns in the dataset. 

*** Description of data in the dataset ***
The data is included per patient. Both a .csv file and a .xls file has been given. 
							
