| Variables* | RR (95% CI)† | ||
| NE→class A–B | Class A–B→NE | Net effect | |
| Age ⩾65 years | 1.19 (0.95 to 1.48) | 1.02 (0.78 to 1.34) | 1.17 (0.91 to 1.50) |
| Male | 2.36 (1.79 to 3.13)‡ | 0.55 (0.40 to 0.74)‡ | 4.33 (3.30 to 5.66)‡ |
| Body mass index ⩾27 kg/m2 | 1.28 (1.01 to 1.65)‡ | 0.70 (0.52 to 0.96)‡ | 1.81 (1.36 to 2.41)‡ |
| Smoker | 2.27 (1.68 to 3.06)‡ | 1.38 (0.96 to 1.97) | 1.65 (1.24 to 2.18)‡ |
| Alcohol use | 1.32 (1.08 to 1.62)‡ | 0.99 (0.78 to 1.26) | 1.34 (1.07 to 1.69)‡ |
| Chronic disease | |||
| Cardiac | 0.28 (0.07 to 1.16) | 1.19 (0.59 to 2.39) | 0.23 (0.06 to 1.02) |
| Pulmonary | 0.98 (0.58 to 1.65) | 0.53 (0.19 to 1.45) | 1.86 (0.72 to 4.80) |
| Hepatic | 1.01 (0.76 to 1.34) | 1.09 (0.79 to 1.54) | 0.92 (0.67 to 1.26) |
| Peptic ulcer disease | 1.17 (0.92 to 1.49) | 0.88 (0.66 to 1.17) | 1.33 (1.02 to 1.75)‡ |
| Cholesterol ⩾200 mg/dl | 0.86 (0.63 to 1.19) | 0.52 (0.34 to 0.79)‡ | 1.66 (1.08 to 2.55)‡ |
| Hyperuricaemia and/or history of gout | 1.46 (1.06 to 1.99)‡ | 0.90 (0.61 to 1.34) | 1.61 (1.12 to 2.33)‡ |
| Metabolic syndrome | 1.42 (1.11 to 1.80)‡ | 0.76 (0.55 to 0.97)‡ | 1.87 (1.40 to 2.51)‡ |
| Enlarged waist circumference | 1.02 (0.84 to 1.25) | 0.78 (0.61 to 0.99)‡ | 1.31 (1.04 to 1.65)‡ |
| Hypertension or blood pressure ⩾130/85 mm Hg | 1.32 (1.04 to 1.68)‡ | 0.87 (0.64 to 1.17) | 1.53 (1.15 to 2.04)‡ |
| Diabetes or fasting glucose ⩾110 mg/dl | 1.00 (0.68 to 1.48) | 0.68 (0.42 to 1.09) | 1.48 (0.91 to 2.41) |
| HDL-C <40 mg/dl | 1.39 (1.15 to 1.68)‡ | 1.00 (0.79 to 1.26) | 1.39 (1.12 to 1.73)‡ |
| Triglycerides ⩾150 mg/dl | 1.17 (0.95 to 1.45) | 0.71 (0.55 to 0.91)‡ | 1.66 (1.30 to 2.12)‡ |
| Exercise frequency | 0.94 (0.76 to 1.17) | 1.11 (0.87 to 1.45) | 0.84 (0.67 to 1.07) |
| Sleep quality | 1.03 (0.77 to 1.38) | 1.12 (0.81 to 1.54) | 0.92 (0.68 to 1.25) |
| Symptoms of GORD | 1.23 (0.93 to 1.63) | 0.76 (0.54 to 1.05) | 1.64 (1.18 to 2.27)‡ |
| Short-term use of PPI or H2RA | 1.31 (0.86 to 1.97) | 2.83 (2.14 to 3.71)‡ | 0.46 (0.33 to 0.65)‡ |
*Factors were dichotomsed (no/yes) as follows: age ⩾65 years, male, body mass index ⩾27 kg/m2, smoker, alcohol consumed ⩾ once per week, metabolic syndrome, exercise more than twice per week, poor sleep quality, symptoms of GORD and use of short-term PPI or H2RA. The “no” group constitutes the baseline comparator.
†The RR for evaluating the role of each factor was arrived at by taking the exponential of the regression coefficient (β) of the Markov regression—that is, exp(β1) for progression, exp(β2) for regression and exp(β1–β2) for the net effect.
‡p<0.05.
GORD, gastro-oesophageal reflux disease; HDL-C, high-density lipoprotein cholesterol; H2RA, histamine-2 receptor antagonist; PPI, proton pump inhibitor.