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Table 4 Comparison of the complete-case dataset and the dataset with imputed values (multiple imputation), the Norwegian Women and Cancer Study, 1996–2013

From: Coffee consumption and the risk of malignant melanoma in the Norwegian Women and Cancer (NOWAC) Study

Characteristics Missing, N(%) Complete-case Multiple imputation
Total coffee consumption-baseline, mean (SD) 0 (0.0) 3.9 (2.5) 3.9 (2.5)
Total coffee consumption-follow-up, mean (SD) 21,011 (22.9) 3.4 (2.2) 3.4 (2.2)
Filtered coffee consumption-baseline, mean (SD) 0 (0.0) 2.6 (2.4) 2.6 (2.4)
Filtered coffee consumption-follow-up, mean (SD) 27,953 (30.5) 2.5 (2.2) 2.5 (2.2)
Instant coffee consumption-baseline, mean (SD) 0 (0.0) 0.3 (1.1) 0.3 (1.1)
Instant coffee consumption-follow-up, mean (SD) 27,953 (30.5) 0.4 (1.0) 0.4 (1.0)
Boiled coffee consumption-baseline, mean (SD) 0 (0.0) 0.9 (2.0) 0.9 (2.0)
Boiled coffee consumption-follow-up, mean (SD) 27,953 (30.5) 0.5 (1.4) 0.5 (1.4)
Smoking status, %
 Never 1595 (1.5) 34.6 34.7
 Former 32.2 32.2
 Current 33.1 33.1
Duration of education (y), mean (SD) 5184 (5.0) 12.1 (3.4) 12.0 (3.4)
Body mass index, mean (SD) 2379 (2.3) 24.0 (3.8) 24.0 (3.8)
Physical activity level, mean (SD) 9560 (9.2) 5.6 (1.9) 5.6 (1.9)
Alcohol consumption (g/day), mean (SD) 1686 (1.6) 3.2 (5.4) 3.2 (5.4)
Average number of sunburns per year, mean (SD) 11,103 (10.7) 0.8 (0.7) 0.8 (0.7)
Original hair color, %
 Dark 1587 (1.5) 17.3 17.3
 Brown 39.7 39.6
 Blond 40.0 40.1
 Ginger 3.0 3.0
Number of moles larger than 5 mm, %
 0 10,444 (10.0) 88.6 88.7
 1 6.6 6.6
 2–3 3.2 3.2
 4–6 0.9 0.9
 7–12 0.4 0.4
 13–24 0.1 0.1
 ≥25 0.1 0.1
Area of residence 0 (0.0)   
 Oslo area 8.9 8.9
 Eastern Norway 35.1 35.1
 Southern Norway 4.7 4.7
 Western Norway 21.5 21.5
 Middle Norway 8.0 8.0
 Northern Norway 21.8 21.8
  1. y years, SD standard deviation