Test
", "MG
", "Sunday, July 13, 2014
", "All analyses were performed using R (ver. 3.1.1)[R Core Team, 2013] and packages rms (ver. 4.2-0) [F. Harrell, 2014] for analysis, Gmisc for plot and table output (ver. 0.6.6), and knitr (ver ) [Xie, 2013] for reproducible research.
", "Results
", "We found 205 patients with malignant melanoma between the years 1962 and 1977. Patients were followed until the end of 1977, the median follow-up time was 5.5 years (range 0.0 to 15.2 years). Males were more common than females and had also a higher mortality rate.
", "| ", " ", "Table 1: Baseline characteristics", " | |||||
| ", " | ", " ", " | ", "", "Death", " | ", "|||
|---|---|---|---|---|---|
| ", " ", " | ", "", "Total", " | ", "", "Alive", " | ", "", " ", " | ", "", "Melanoma", " | ", "", "Non-melanoma", " | ", "
| ", "Sex", " | |||||
| ", " Male", " | ", "", "126 (61%)", " | ", "", "91 (72%)", " | ", "", " ", " | ", "", "28 (22%)", " | ", "", "7 (6%)", " | ", "
| ", " Female", " | ", "", "79 (39%)", " | ", "", "43 (54%)", " | ", "", " ", " | ", "", "29 (37%)", " | ", "", "7 (9%)", " | ", "
| ", "Age†", " | |||||
| ", " Mean (SD)", " | ", "", "52 (± 17)", " | ", "", "50 (± 16)", " | ", "", " ", " | ", "", "55 (± 18)", " | ", "", "65 (± 11)", " | ", "
| ", "Ulceration", " | |||||
| ", " Absent", " | ", "", "115 (56%)", " | ", "", "92 (80%)", " | ", "", " ", " | ", "", "16 (14%)", " | ", "", "7 (6%)", " | ", "
| ", " Present", " | ", "", "90 (44%)", " | ", "", "42 (47%)", " | ", "", " ", " | ", "", "41 (46%)", " | ", "", "7 (8%)", " | ", "
| ", "Thickness‡", " | |||||
| ", " Mean (SD)", " | ", "", "2.9 (±3.0)", " | ", "", "2.2 (±2.3)", " | ", "", " ", " | ", "", "4.3 (±3.6)", " | ", "", "3.7 (±3.6)", " | ", "
| ",
" ", "† Age at the time of surgery. ‡ Tumour thicknes, also known as Breslow thickness, measured in mm.", " | |||||
Main results
", "| ", " ", "Table 2: Adjusted and unadjusted estimates for melanoma specific death.", " | ||||||||
| ", " | ", " ", " | ", "", "Crude", " | ", "", "Adjusted", " | ", "|||||
|---|---|---|---|---|---|---|---|---|
| ", "Variable", " | ", "", "Total", " | ", "", "Event", " | ", "", " ", " | ", "", "HR", " | ", "", "2.5 % to 97.5 %", " | ", "", " ", " | ", "", "HR", " | ", "", "2.5 % to 97.5 %", " | ", "
| ", "Sex", " | ||||||||
| ", " Male", " | ", "", "126", " | ", "", "28 (22%)", " | ", "", " ", " | ", "", "1", " | ", "", "ref", " | ", "", " ", " | ", "", "1", " | ", "", "ref", " | ", "
| ", " Female", " | ", "", "79", " | ", "", "29 (37%)", " | ", "", " ", " | ", "", "1.94", " | ", "", "1.15 to 3.26", " | ", "", " ", " | ", "", "1.54", " | ", "", "0.91 to 2.60", " | ", "
| ", "Age", " | ", "", "52 (± 17)", " | ", "", "55 (± 18)", " | ", "", " ", " | ", "", "1.02", " | ", "", "1.00 to 1.04", " | ", "", " ", " | ", "", "1.01", " | ", "", "1.00 to 1.03", " | ", "
| ", "Ulceration", " | ||||||||
| ", " Absent", " | ", "", "115", " | ", "", "16 (14%)", " | ", "", " ", " | ", "", "1", " | ", "", "ref", " | ", "", " ", " | ", "", "1", " | ", "", "ref", " | ", "
| ", " Present", " | ", "", "90", " | ", "", "41 (46%)", " | ", "", " ", " | ", "", "4.36", " | ", "", "2.44 to 7.77", " | ", "", " ", " | ", "", "3.20", " | ", "", "1.75 to 5.88", " | ", "
| ", "Breslow thickness", " | ", "", "3 (± 3)", " | ", "", "4 (± 4)", " | ", "", " ", " | ", "", "1.17", " | ", "", "1.10 to 1.25", " | ", "", " ", " | ", "", "1.12", " | ", "", "1.04 to 1.20", " | ", "
After adjusting for the three variables, age, sex, tumor thickness and ulceration, only the latter two remained significant (p-value < 0.001 and 0.004), see table 1 and figure I.
", "
",
"There was no strong indication for non-linearity for any of the continuous variables although the impact of thickness did seem to lessen above 4 mm, see figure II.
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