Can synthetic data reproduce real-world findings in epidemiology? A replication study using adversarial random forests
Organizations: Leibniz Institute for Prevention Research and Epidemiology—BIPS, Bremen, Germany · Faculty of Mathematics and Computer Science, University of Bremen, Bremen, Germany · Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada · Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany ·
Abstract
Synthetic data hold substantial potential to address practical challenges in epidemiology due to restricted data access and privacy concerns. However, many current methods suffer from limited quality, high computational demands, and complexity for non-experts. Furthermore, common evaluation strategies for synthetic data often fail to directly reflect statistical utility and measure privacy risks sufficiently. Against this background, a critical underexplored question is whether synthetic data can reliably reproduce key findings from epidemiological research while preserving privacy. We propose adversarial random forests (ARF) as an efficient and convenient method for synthesizing tabular epidemiological data. To evaluate its performance, we replicated statistical analyses from six epidemiological publications covering blood pressure, anthropometry, myocardial infarction, accelerometry, loneliness, and diabetes, from the German National Cohort (NAKO Gesundheitsstudie), the Bremen STEMI Registry U45 Study, and the Guelph Family Health Study. We further assessed how dataset dimensionality and variable complexity affect the quality of synthetic data, and contextualized ARF's performance by comparison with commonly used tabular data synthesizers in terms of utility, privacy, generalization, and runtime. Across all replicated studies, results on ARF-generated synthetic data consistently aligned with original findings. Even for datasets with relatively low sample size-to-dimensionality ratios, replication outcomes closely matched the original results across descriptive and inferential analyses. Reduced dimensionality and variable complexity further enhanced synthesis quality. ARF demonstrated favourable performance regarding utility, privacy preservation, and generalization relative to other synthesizers and superior computational efficiency.
Figures & tables
| Publication | Data source | Research topic | (num/cat/lvls) | ||||
|---|---|---|---|---|---|---|---|
| Schikowski et al. [ 36 ] | NAKO | Blood pressure | 98 332 | 7 (5/2/4) | 0 | 0 | 0 |
| Fischer et al. [ 15 ] | NAKO | Anthropometry | 101 557 | 12 (10/2/20) | 97 903 | 9 | 34.43 |
| Wienbergen et al. [ 43 ] | NAKO, BSR-U45 | Myocardial infarction | 1713 | 12 (3/9/24) | 176 | 1 | 0.86 |
| Breau et al. [ 3 ] | GFHS | Accelerometry | 262 | 28 (25/3/34) | 16 | 2 | 0.23 |
| Berger et al. [ 1 ] | NAKO | Loneliness/COVID-19 | 113 527 | 47 (3/44/230) | 0 | 0 | 0 |
| Tanoey et al. [ 39 ] | NAKO | Type 1 diabetes | 101 570 | 19 (7/12/42) | 100 621 | 6 | 12.66 |
| Variable | Value cases | Proportion cases | Value controls | Proportion controls |
|---|---|---|---|---|
| Number of participants (n) | 522 (485-560) | 1191 (1153-1228) | ||
| 522 (486-560) | 1191 (1153-1227) | |||
| Age (years) (median) | 42 (42-43) | 42 (41-42) | ||
| 41 (41-42) | 41 (40-41) | |||
| Age (years) (1st quartile) | 39 (38-39) | 38 (37-38) | ||
| 38 (38-39) | 37 (37-38) |
Appendix figures & tables44 assets
Supplementary material from the paper’s appendix.
Appendix
| Sex | Age group | Blood pressure measure | Avg. meas. 1/2 - meas. 2 (mean) |
| Male | 20-24 | Systolic | 1.72 (1.51-1.91) |
| 1.61 (1.34-1.88) | |||
| Diastolic | 0.87 (0.73-1.02) | ||
| 0.87 (0.68-1.07) | |||
| 25-34 | Systolic | 1.26 (1.17-1.35) | |
| 1.32 (1.21-1.45) |
| Sex | Age group | Blood pressure measure | Aggregation | Value |
| Male | 20-24 | Systolic | Mean | 126.22 (125.50-126.91) |
| 126.01 (125.09-126.97) | ||||
| SD | 11.47 (10.91-12.00) | |||
| 11.22 (10.59-11.90) | ||||
| Diastolic | Mean | 72.14 (71.64-72.65) | ||
| 72.39 (71.69-73.24) |
| Sex | Age group | Hypertension status | Proportion using avg. meas. 1/2 | Proportion using meas. 2 |
| Male | 20-24 | Normotension | 0.82 (0.79-0.84) | 0.83 (0.81-0.85) |
| 0.83 (0.80-0.86) | 0.84 (0.81-0.87) | |||
| Hypertension known controlled | 0.03 (0.02-0.04) | 0.03 (0.02-0.04) | ||
| 0.03 (0.02-0.04) | 0.03 (0.02-0.04) | |||
| Hypertension known uncontrolled | 0.02 (0.01-0.02) | 0.01 (0.01-0.02) | ||
| 0.01 (0.01-0.02) | 0.01 (0.01-0.02) |
| Variable | Sex | Age group | n | Mean | SD | 10th percentile | 50th perecentile | 90th percentile |
| Height | Male | 20-29 | 2899 (2798-2999) | 180.75 (180.50-181.01) | 7.14 (6.90-7.38) | 171.90 (171.50-172.40) | 180.70 (180.40-181.10) | 189.90 (189.50-190.20) |
| 2210 (2044-2462) | 180.19 (179.58-180.71) | 7.31 (6.96-7.76) | 170.98 (169.76-171.80) | 180.30 (179.70-180.90) | 189.38 (188.70-189.95) | |||
| 30-39 | 4168 (4048-4296) | 180.66 (180.45-180.88) | 7.15 (7.00-7.30) | 171.50 (171.10-171.80) | 180.60 (180.30-180.80) | 189.60 (189.21-190.00) | ||
| 4933 (4572-5155) | 179.95 (179.16-180.40) | 7.47 (7.18-8.05) | 170.40 (168.90-171.20) | 180.00 (179.40-180.50) | 189.30 (188.90-189.70) | |||
| 40-49 | 9431 (9241-9621) | 179.83 (179.69-179.97) | 7.14 (7.01-7.29) | 170.80 (170.60-171.10) | 179.90 (179.70-180.00) | 188.80 (188.50-189.00) | ||
| 9799 (93312-10253) | 179.17 (178.34-179.62) | 7.45 (7.17-8.01) | 169.70 (168.10-170.50) | 179.30 (178.60-179.70) | 188.50 (188.20-188.90) |
| Study centre | Height men (mean) | Height women (mean) |
| Augsburg | 176.83 (176.63-177.03) | 163.66 (163.48-163.84) |
| 176.64 (176.19-176.96) | 164.34 (164.03-164.90) | |
| Berlin Mitte | 178.17 (177.90-178.45) | 165.25 (165.02-165.47) |
| 177.67 (177.05-178.12) | 165.53 (165.19-166.06) | |
| Berlin Nord | 177.60 (177.30-177.89) | 164.70 (164.47-164.92) |
| 177.34 (176.70-177.77) | 165.20 (164.84-165.86) |
| Sex | Age group | BMI group | Proportion |
| Male | 20-29 | Overweight | 0.30 (0.28-0.31) |
| 0.30 (0.28-0.32) | |||
| Obese | 0.10 (0.09-0.11) | ||
| 0.09 (0.08-0.11) | |||
| 30-39 | Overweight | 0.39 (0.38-0.41) | |
| 0.38 (0.37-0.40) |
| Study centre | BMI men (mean) | BMI women (mean) |
| Augsburg | 27.91 (27.78-28.05) | 26.81 (26.66-26.97) |
| 27.93 (27.77-28.09) | 26.84 (26.66-27.03) | |
| Berlin Mitte | 26.74 (26.59-26.90) | 25.45 (25.27-25.62) |
| 26.90 (26.70-27.12) | 25.57 (25.36-25.81) | |
| Berlin Nord | 27.71 (27.53-27.90) | 26.41 (26.23-26.60) |
| 27.65 (27.45-27.86) | 26.44 (26.23-26.66) |
| Variable | Value cases | Proportion cases | Value controls | Proportion controls |
| Number of participants (n) | 522 (485-560) | 1191 (1153-1228) | ||
| 522 (486-560) | 1191 (1153-1227) | |||
| Age (years) (median) | 42 (42-43) | 42 (41-42) | ||
| 41 (41-42) | 41 (40-41) | |||
| Age (years) (1st quartile) | 39 (38-39) | 38 (37-38) | ||
| 38 (38-39) | 37 (37-38) |
| Adj. level | Variable | Odds ratio | 2.5% | 97.5% |
| 1 | Smoking status: Former | 1.00 (0.62-1.59) | 0.63 (0.38-1.00) | 1.60 (1.01-2.54) |
| 1.09 (0.68-1.66) | 0.70 (0.43-1.07) | 1.68 (1.08-2.58) | ||
| Smoking status: Current | 10.75 (7.87-15.80) | 7.60 (5.61-10.79) | 15.21 (10.98-23.13) | |
| 8.66 (6.14-12.45) | 6.25 (4.52-8.75) | 12.02 (8.37-17.78) | ||
| Alcohol consumption: 1x/month | 1.04 (0.69-1.54) | 0.70 (0.46-1.04) | 1.53 (1.03-2.30) | |
| 1.03 (0.70-1.55) | 0.70 (0.48-1.06) | 1.52 (1.02-2.28) |
| Subset | Adj. level | No. risk factors | Odds ratio | 2.5% | 97.5% |
| All | 1 | 1 | 5.40 (3.08-12.42) | 2.88 (1.80-5.20) | 10.11 (5.28-29.45) |
| 4.40 (2.58-8.95) | 2.48 (1.57-4.28) | 7.81 (4.20-19.06) | |||
| 2+ | 43.81 (25.52-97.73) | 23.27 (14.85-41.49) | 82.48 (43.44-229.52) | ||
| 30.91 (17.28-64.17) | 17.44 (10.68-30.29) | 54.41 (28.09-139.38) | |||
| 1 unit increase | 6.41 (5.25-8.16) | 5.12 (4.26-6.40) | 8.01 (6.47-10.39) | ||
| 5.32 (4.18-6.81) | 4.33 (3.47-5.44) | 6.53 (5.05-8.52) |
| Variable | Everyone | Toddlers 1.5-2 yrs | Preschoolers 3-4 yrs | Preschoolers 3-6 yrs | School aged 5-6 yrs |
| Number of participants (n) | 262 (262-262) | 96 (80-111) | 121 (105-136) | 166 (151-182) | 45 (34-57) |
| 262 (262-262) | 84 (69-100) | 143 (126-159.02) | 178 (162-193) | 35 (24-48) | |
| Age (years) (mean) | 3.62 (3.46-3.77) | 2.26 (2.17-2.34) | 3.96 (3.86-4.06) | 4.40 (4.26-4.54) | 5.58 (5.49-5.68) |
| 3.64 (3.50-3.78) | 2.39 (2.30-2.47) | 3.94 (3.84-4.03) | 4.23 (4.12-4.36) | 5.44 (5.34-5.54) | |
| Age (years) (SD) | 1.28 (1.20-1.35) | 0.42 (0.38-0.45) | 0.59 (0.54-0.64) | 0.90 (0.83-0.96) | 0.33 (0.27-0.37) |
| 1.10 (1.03-1.18) | 0.38 (0.33-0.42) | 0.56 (0.52-0.60) | 0.79 (0.72-0.86) | 0.30 (0.23-0.36) |
| Set of cutpoints | SED | LPA | MVPA |
| van Cauwenberghe | 615.34 (607.77-623.08) | 31.81 (30.92-32.68) | 67.09 (64.70-69.44) |
| 614.10 (606.94-620.96) | 31.88 (30.99-32.73) | 67.22 (64.97-69.54) | |
| Pate | 574.95 (567.58-582.27) | 48.54 (47.33-49.75) | 90.75 (87.77-93.69) |
| 573.58 (566.89-579.93) | 48.67 (47.47-49.84) | 90.92 (88.07-93.83) | |
| Puyau | 574.95 (567.58-582.27) | 93.60 (91.17-96.06) | 45.69 (43.94-47.51) |
| 573.61 (566.97-580.11) | 93.73 (91.37-96.15) | 45.82 (44.07-47.61) |
| Age group | Set of cutpoints | SED | LPA | MVPA |
| Toddlers (1.5-2 years) | Trost | 491.66 (479.62-503.62) | 107.73 (103.48-111.87) | 82.01 (77.21-86.77) |
| 501.96 (488.56-513.23) | 105.80 (101.54-110.26) | 80.77 (76.03-85.99) | ||
| Costa (VA) | 477.97 (465.90-489.90) | 132.69 (127.62-137.62) | 70.75 (66.49-75.13) | |
| 488.53 (475.31-499.88) | 130.24 (125.12-135.73) | 69.67 (65.49-74.12) | ||
| Costa (VM) | 449.33 (438.15-461.16) | 157.79 (151.94-163.57) | 74.28 (69.63-78.73) | |
| 456.76 (443.80-468.22) | 157.03 (151.06-163.17) | 74.46 (69.94-79.37) |
| Age group | Set of cutpoints | Proportion meeting PA guideline |
| Toddlers (1.5-2 years) | Trost | 0.62 (0.53-0.72) |
| 0.59 (0.48-0.71) | ||
| Costa (VA) | 0.72 (0.62-0.80) | |
| 0.70 (0.60-0.80) | ||
| Costa (VM) | 0.90 (0.83-0.95) | |
| 0.88 (0.80-0.95) |
| Variable | Value |
| Number of participants (n) | 113527 (113527-113527) |
| 113527 (113527-113527) | |
| 113527 (113527-113527) | |
| Sex: Female (%) | 51.75 (51.47-52.03) |
| 51.76 (51.45-52.05) | |
| 51.76 (51.46-52.05) |
| Variable | Value | Value woman | Value men |
| Feeling of missing company of others (%) | 79.88 (79.64-80.11) | 83.49 (83.17-83.79) | 76.00 (75.63-76.36) |
| 79.87 (79.63-80.10) | 82.31 (81.91-82.72) | 77.24 (76.79-77.69) | |
| Feeling of being left out (%) | 29.88 (29.62-30.16) | 35.09 (34.70-35.47) | 24.29 (23.92-24.67) |
| 29.88 (29.61-30.14) | 34.11 (33.67-34.55) | 25.34 (24.89-25.77) | |
| Feeling of being socially isolated (%) | 34.87 (34.61-35.15) | 40.48 (40.07-40.89) | 28.85 (28.47-29.22) |
| 34.87 (34.58-35.17) | 39.28 (38.79-39.79) | 30.14 (29.62-30.65) |
| Variable | beta coefficient | 2.5% | 97.5% |
| (Intercept) | 4.34 (4.27-4.41) | 4.27 (4.20-4.34) | 4.41 (4.34-4.48) |
| 4.30 (4.23-4.37) | 4.24 (4.16-4.31) | 4.37 (4.29-4.44) | |
| 4.40 (4.32-4.49) | 4.33 (4.25-4.41) | 4.47 (4.39-4.56) | |
| Age | 0.00 (-0.00-0.00) | -0.00 (-0.00-0.00) | 0.00 (0.00-0.00) |
| -0.00 (-0.00-0.00) | -0.00 (-0.00–0.00) | 0.00 (-0.00-0.00) | |
| 0.00 (-0.00-0.00) | -0.00 (-0.00-0.00) | 0.00 (-0.00-0.00) |
| Sex | Age group | Lonely participants (proportion) | Participants with increased loneliness (proportion) |
| Male | 20-29 | 0.33 (0.32-0.35) | 0.58 (0.57-0.60) |
| 0.33 (0.31-0.35) | 0.57 (0.55-0.59) | ||
| 30-39 | 0.29 (0.28-0.30) | 0.50 (0.48-0.51) | |
| 0.30 (0.29-0.31) | 0.51 (0.50-0.53) | ||
| 40-59 | 0.26 (0.25-0.26) | 0.45 (0.44-0.46) | |
| 0.26 (0.25-0.27) | 0.46 (0.45-0.47) |
| Sex | Loneliness score | PHQ-9 score COVID survey (mean) | GAD-7 score COVID survey (mean) |
| Male | 3 | 2.56 (2.51-2.61) | 2.01 (1.96-2.05) |
| 2.38 (2.28-2.46) | 1.87 (1.79-1.94) | ||
| 4 | 2.63 (2.59-2.67) | 2.09 (2.06-2.13) | |
| 2.65 (2.59-2.70) | 2.11 (2.06-2.15) | ||
| 5 | 3.46 (3.39-3.53) | 2.77 (2.71-2.83) | |
| 3.62 (3.54-3.70) | 2.93 (2.87-3.00) |
| Sex | Lonely | PHQ-9 score baseline examination (mean) | GAD-7 score baseline examination (mean) |
| Male | Yes | 4.17 (4.10-4.24) | 3.37 (3.31-3.42) |
| 4.19 (4.11-4.28) | 3.42 (3.35-3.49) | ||
| No | 2.90 (2.87-2.93) | 2.30 (2.27-2.32) | |
| 2.93 (2.89-2.97) | 2.33 (2.30-2.36) | ||
| Female | Yes | 4.79 (4.73-4.84) | 4.01 (3.96-4.06) |
| 4.76 (4.68-4.85) | 3.98 (3.91-4.06) |
| Variable | Agg. | No diabetes | Diabetes type 1 | Diabetes type 2 | Total |
| Number of participants (n) | 94408 (94252-94569) | 371 (331-410) | 6574 (6420-6724) | 101353 (101324-101381) | |
| 94407 (94250-94562) | 311 (270-351) | 5847 (5477-6188) | 100576 (100217-100884) | ||
| 94411 (94252-94563) | 371 (333-412) | 6571 (6429-6727) | 101353 (101353-101353) | ||
| Sex: Male | n | 43244 (42932-43555) | 204 (175-233) | 3602 (3489-3719) | 47050 (46735-47362) |
| 43267 (42956-43586) | 156 (130-183) | 3164 (2942-3397) | 46587 (46222-46949) | ||
| 43264 (42953-43555) | 199 (171-227) | 3588 (3477-3707) | 47046 (46737-47346) |
| Variable | Model | Age at diagnosis | Hazard ratio | 2.5% | 97.5% |
| Birth order: First | Univariable | 0–40 | 0.83 (0.61-1.14) | 0.61 (0.45-0.82) | 1.12 (0.83-1.57) |
| 1.06 (0.72-1.63) | 0.72 (0.49-1.04) | 1.58 (1.05-2.56) | |||
| Birth order: Second | 0.69 (0.50-0.96) | 0.50 (0.36-0.69) | 0.94 (0.69-1.34) | ||
| 0.97 (0.65-1.51) | 0.65 (0.44-0.98) | 1.44 (0.95-2.37) | |||
| Birth order: =Third | 0.66 (0.45-0.96) | 0.46 (0.30-0.67) | 0.95 (0.66-1.38) | ||
| 0.97 (0.63-1.51) | 0.63 (0.41-0.96) | 1.48 (0.95-2.39) |
| Variable | Hazard ratio | 2.5% | 97.5% |
| Birth order: First | 0.83 (0.61-1.14) | 0.61 (0.45-0.82) | 1.12 (0.83-1.57) |
| 1.06 (0.72-1.63) | 0.72 (0.49-1.04) | 1.58 (1.05-2.56) | |
| 0.84 (0.62-1.17) | 0.62 (0.46-0.85) | 1.14 (0.85-1.61) | |
| Birth order: Second | 0.69 (0.49-0.96) | 0.50 (0.36-0.69) | 0.94 (0.68-1.35) |
| 0.97 (0.65-1.51) | 0.65 (0.44-0.98) | 1.44 (0.95-2.37) | |
| 0.70 (0.51-0.97) | 0.51 (0.37-0.70) | 0.97 (0.71-1.35) |
| Sex | Age at diagnosis | Therapy | n |
| Male | 0-15 | With insulin | 36 (25-48) |
| 15 (8-24) | |||
| 42 (28-56) | |||
| Unknown | 13 (6-21) | ||
| 6 (2-12) | |||
| 12 (6-20) |
| Publication | Key variables | Target variable |
|---|---|---|
| Schikowski et al. [ 36 ] | Age , Sex | Hypertension |
| Fischer et al. [ 15 ] | Age , Sex , Height , Weight , Study Center | VAT |
| Wienbergen et al. [ 43 ] | Age , Sex , BMI , Education , Birth Germany | EOMI |
| Breau et al. [ 3 ] | Age , Sex , Weight , Height , Ethnicity | Income Household |
| Berger et al. [ 1 ] | Age , Sex , Study Center , Education | Suicidal Ideation |
| Tanoey et al. [ 39 ] | Age , Sex , Height , Migration Background | Diabetes |
Synthetic Tabular Data Generation
Synthetic tabular data generation creates artificial records that preserve useful feature relationships while limiting exposure of sensitive data.
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