Table 2.

Summary of the key predictor variables in the classification accuracy of future anxiety disorder by the random forest algorithm.

Variable	UK Biobank ID	Direction of movement (in anxiety compared to control)	Representative mean decrease Gini coefficient (relative importance)
			1–5 years prospective anxiety	All years prospective anxiety
Neuroticism score	20127	↑	93.7	465.4
Number of self-reported non-cancer illnesses	135	↑	31.4	122.2
Urea	30670	↓	26.3	98.5
Total bilirubin	30840	↓	24.7	112.8
GlycA	23480	↑	24.7	96.6
Townsend deprivation index	22189	↑	24.5	106.0
Alkaline phosphatase	30610	↑	23.7	101.7
Histidine	23463	↓	23.7	99.3
IGF-1	30770	↓	23.6	96.7
Monocyte (%)	30190	↓	23.2	96.5
C-reactive protein	30710	↑	23.2	94.1
Red blood cell (erythrocyte) distribution width	30070	↑	22.9	92.5
Urate	30880	↓	22.6	100.3
Platelet count	30080	↑	22.6	93.3
Creatinine (measured by enzymatic analysis)	30700	↓	22.5	108.5
Body mass index (BMI)	21001	↑	22.5	97.7
Platelet crit	30090	↑	21.9	90.9
Haematocrit (%)	30030	↓	21.8	95.1
Haemoglobin concentration	30020	↓	21.7	99.4
Number of treatments/medications taken	137	↑	21.5	111.4
Red blood cell (erythrocyte) count	30010	↓	21.4	96.7
Creatinine	23478	↓	21.3	104.4
Leucine	23466	↓	21.2	90.7
Total concentration of branched-chain amino acids	23464	↓	21.2	88.9
Overall health rating (%)	2178	↓	10.7	46.4
Pain	6159	↑	10.4	39.5
Long-standing illness, disability or infirmity	2188	↑	9.9	45.5
Too sick for employment	6142	↑	6.5	NA

Note: ↑ refers to an increase in anxious individuals compared to controls, ↓ refers to a decrease in anxious individuals compared to controls.