Table 1

 Unadjusted matched odds ratios for diarrhoeal disease and selected risk factors in all infants

Cases (%)Controls (%)OR (95% CI)
*Refers to main wage earner.
†Crowding  =  (no. persons in house excluding the infant)/no. rooms.
‡Excluding currently breast fed and never breast fed infants.
§In formula/mixed fed infants.
EBM, exclusive breast milk.
Sex
    Male105 (58%)74 (52%)1
    Female77 (42%)68 (48%)0.76 (0.48 to 1.19)
p = 0.23
Social class*
    I–III131 (75%)122 (86%)1
    IV–V/other44 (25%)20 (14%)2.14 (1.19 to 3.85)
p = 0.011
Accommodation
    Own/mortgage116 (65%)109 (77%)1
    Rent—private15 (8%)12 (8%)1.33 (0.59 to 3.01)
    Rent—council47 (26%)21 (15%)2.46 (1.31 to 4.59)
p = 0.014
Travel in past 10 days
    No154 (86%)121 (87%)1
    Holiday6 (3%)9 (6%)0.47 (0.16 to 1.37)
    Other20 (11%)9 (6%)1.67 (0.74 to 3.80)
p = 0.15
Regular use of food mixer
    No62 (34%)28 (20%)1
    Yes119 (66%)114 (80%)0.44 (0.25 to 0.76)
p = 0.003
Attends crèche/nursery
    No162 (89%)127 (89%)1
    Yes20 (11%)16 (11%)0.99 (0.49 to 2.00)
p = 0.98
Crowding†
    <1102 (71%)82 (68%)1
    ⩾141 (29%)39 (32%)0.94 (0.55 to 1.59)
p = 0.81
Contact with person with diarrhoea/vomiting in household
    No148 (81%)132 (92%)1
    Yes32 (19%)11 (8%)2.62 (1.27 to 5.39)
p = 0.006
Contact with person with diarrhoea/vomiting outside household
    No97 (54%)112 (78%)1
    Yes29 (16%)11 (8%)3.02 (1.43 to 6.39)
    Not sure54 (30%)20 (14%)3.30 (1.79 to 6.10)
p<0.001
Current feeding
    EBM11 (7%)23 (17%)1
    Mixed11 (7%)15 (11%)1.63 (0.55 to 4.85)
    Formula145 (87%)99 (72%)3.28 (1.48 to 7.23)
p = 0.004
Duration of breast feeding (months)
    Currently breast fed22 (13%)38 (28%)1
    ⩾6 months, currently formula fed16 (10%)8 (6%)3.97 (1.38 to 11.44)
    3–5 months, currently formula fed25 (15%)28 (21%)1.71 (0.78 to 3.75)
    ⩽2 months, currently formula fed38 (23%)32 (24%)2.14 (1.03 to 4.47)
    Never breast fed63 (38%)28 (21%)3.87 (1.90 to 7.87)
p = 0.002, p = 0.28‡
Months since breast feeding cessation
    Currently breast fed22 (13%)38 (28%)1
    ⩽2 months17 (10%)18 (13%)1.68 (0.71 to 3.93)
    3–5 months30 (18%)21 (16%)2.24 (1.02 to 4.92)
    ⩾6 months32 (20%)29 (22%)2.57 (1.11 to 5.95)
    Never breast fed63 (38%)28 (21%)3.92 (1.92 to 7.99)
p = 0.004, p = 0.70‡
Sterilisation of bottles§
    Chemical78 (47%)51 (44%)1
    Boiling water14 (8%)3 (3%)3.81 (1.01 to 14.45)
    Steam60 (36%)54 (47%)0.73 (0.44 to 1.22)
    Other/combination15 (9%)7 (6%)1.42 (0.54 to 3.70)
p = 0.035