Table 2.
Characteristics of participants
| Baseline | Follow-up | ||||||
|---|---|---|---|---|---|---|---|
| Random (n = 306) | Volunteer (n = 113) | Random followed from baseline (n = 101) | Random new (n = 106) | Volunteer followed from baseline (n = 36) | Volunteer new (n = 329) | P value* | |
| Female (%) | 53 | 61 | 56 | 61 | 61 | 58 | 0.25 |
| Age, years range (mean) | 20–88 (58) | 20–84 (49) | 29–90 (64) | 21–90 (60) | 22–83 (60) | 20–89 (52) | 0.49‡ |
| Height, cm mean (SD) | 168 (10) | 167 (8.8) | 166 (9.6) | 166 (10.2) | 168 (8.9) | 167 (10) | 0.38 |
| Weight, kg mean (SD) | 82 (17.1) | 84 (20.6) | 82 (16.9) | 84 (24.1) | 86 (26) | 82 (19.9) | 0.90 |
| BMI, kg/m2 mean (SD) | 29 (5.1) | 30 (6.6) | 29 (5.9) | 30 (7.0) | 30 (8.3) | 29 (6.6) | 0.45 |
| Systolic bp, mmHg mean | 127 | 124 | 127 | 133 | 131 | 126 | 0.10 |
| Diastolic bp, mmHg mean | 79 | 79 | 78 | 81 | 82 | 80 | 0.27 |
| Creatinine mmol mean (SD) | 12.0 (3.8) | 12.0 (4.2) | 11.0 (3.6) | 12.0 (4.3) | 12 (3.8) | 12 (4.4) | 0.31 |
| Urine volume, ml mean (SD) | 1930 (808) | 2012 (868) | 1957 (859) | 2082 (875) | 1867 (747) | 1930 (823) | 0.94 |
| Education (%) | 0.01 | ||||||
| Secondary | 64 | 56 | 55 | 49 | 50 | 45 | |
| Tertiary | 26 | 33 | 40 | 46 | 44 | 47 | |
| Postgraduate | 10 | 12 | 5 | 5 | 6 | 8 | |
| Health Status (%) | |||||||
| Very good | 50 | 49 | 33 | 30 | 19 | 31 | 0.12 |
| Good | 30 | 24 | 42 | 44 | 42 | 43 | |
| Fair | 20 | 27 | 25 | 26 | 39 | 26 | |
| Smoking status (%) | |||||||
| Current smoker (>1/day) | 8 | 22 | 7 | 6 | 14 | 18 | 0.67 |
| Ever smoked (>1/day) | 41 | 53 | 37 | 39 | 50 | 42 | |
| Alcohol consumption (time since last drink) One week or less | 62 | 43 | 58 | 58 | 40 | 53 | |
| 12 months or more | 38 | 57 | 42 | 42 | 60 | 47 | 0.20 |
| Have you ever been told by a nurse of doctor that you have (%) | |||||||
| High blood pressure | 44 | 30 | 55 | 42 | 50 | 40 | 0.02 |
| Heart attack | 8 | 4 | 11 | 9 | 6 | 3 | 0.62 |
| Stroke | 4 | 2 | 6 | 3 | 3 | 2 | 0.57 |
| Angina | 7 | 4 | 8 | 7 | 11 | 5 | 0.93 |
| Diabetes | 11 | 7 | 13 | 15 | 11 | 11 | 0.25 |
| Prescription Medication † (%) | |||||||
| Antihypertensive | 22 | 20 | 37 | 31 | 26 | 23 | 0.03 |
| Lipid lowering | 16 | 18 | 30 | 22 | 14 | 17 | 0.20 |
| Aspirin | 8 | 3 | 21 | 14 | 9 | 8 | 0.01 |
| Glucose lowering | 5 | 9 | 9 | 11 | 12 | 7 | 0.13 |
| Any prescription medication | 66 | 53 | 79 | 83 | 60 | 60 | 0.10 |
*Age comparison presented is for the new random and volunteer sample with the baseline sample, excluding paired participants (the same random and volunteer sample sampled at baseline at follow-up)
†Participants could be taking more than one prescribed medication
‡ p-value compared mean values across all baseline vs. all follow-up