Variables* | RR (95%CI)† | ||

NE→class A–B | Class A–B→NE | Net effect | |

Male | 2.36 (1.73 to 2.97)‡ | 0.53 (0.40 to 0.74)‡ | 4.31 (3.22 to 5.75)‡ |

Smoker | 1.77 (1.32 to 2.36)‡ | 1.48 (0.98 to 2.15) | 1.20 (1.03 to 1.39)‡ |

Metabolic syndrome | 1.29 (1.18 to 1.42)‡ | 0.74 (0.53 to 0.98)‡ | 1.75 (1.29 to 2.38)‡ |

Short-term use of PPI or H2RA | 1.73 (0.92 to 2.77) | 3.19 (2.32 to 4.44)‡ | 0.54 (0.39 to 0.75)‡ |

*Factors were dichotomised (no/yes) as follows: male, smoker, metabolic syndrome and use of short-term use of 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(β

_{1}) for progression, exp(β_{2}) for regression and exp(β_{1}–β_{2}) for the net effect.‡p <0.05.

H2RA, histamine-2 receptor antagonist; PPI, proton pump inhibitor.