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Table 2 Meta-Analyses of Single and Combination of Determinants of Anaemia in Association with Onset of Anaemia abc

From: The effects of single and a combination of determinants of anaemia in the very old: results from the TULIPS consortium

  N event/N total N event/N total HR Weight
(anaemia)d (no anaemia)e (95% CI) %
Iron Deficiency
 Leiden 85-plus Study 6/98 11/262 1.48 (0.64 to 3.40) 30.8
 Newcastle 85+ study 13/109 12/309 2.41 (1.35 to 4.32) 47.6
 TOOTH 4/33 9/64 0.88 (0.30 to 2.53) 21.6
Total (I2 = 32%)    1.67 (0.96 to 2.90) 100.0
Vitamin B12 Deficiency
 Leiden 85-plus Study 16/98 37/262 1.03 (0.59 to 1.79) 40.6
 Newcastle 85+ study 25/109 49/309 1.35 (0.85 to 2.13) 59.4
 TOOTH 0/28 1/54 f 0
Total (I2 = 0%)    1.21 (0.85 to 1.72) 100.0
Folate Deficiency
 Leiden 85-plus Study 10/98 9/262 2.84 (1.45 to 5.54) 51.2
 Newcastle 85+ study 2/109 12/309 0.56 (0.14 to 2.30) 31.9
 TOOTH 1/28 1/54 1.20 (0.11 to 12.91) 17.0
Total (I2 = 54%)    1.46 (0.46 to 4.60) 100.0
Low eGFR
 Leiden 85-plus Study 14/98 40/263 1.09 (0.61 to 1.94) 36.3
 Newcastle 85+ study 41/109 64/309 1.97 (1.32 to 2.94) 52.7
 TOOTH 3/33 0/64 2.41 (0.68 to 8.52) 11.0
Total (I2 = 35%)    1.62 (1.04 to 2.54) 100.0
High CRP
 Leiden 85-plus Study 33/98 64/263 1.55 (1.00 to 2.42) 46.0
 Newcastle 85+ study 29/109 63/308 1.27 (0.83 to 1.95) 48.1
 TOOTH 3/33 3/63 1.45 (0.42 to 5.00) 5.9
Total (I2 = 0%)    1.40 (1.04 to 1.89) 100.0
Increase per Additional Abnormal Determinantc
 Leiden 85-plus Study 41,37,18,2,0,0/98 139,91,30,2,0,0/263 1.35 (1.06 to 1.73) 44.0
 Newcastle 85+ study 30,52,23,4,0,0/109 149,124,32,4, 0,0/309 1.58 (1.25 to 1.98) 50.3
 TOOTH 23,9,1,0,0,0/33 50,14,0,0,0,0/64 1.28 (0.65 to 2.53) 5.7
Total (I2 = 0%)    1.46 (1.24 to 1.71) 100.0
≥2 Combination of Determinantsc
 Leiden 85-plus Study 20/98 33/263 1.87 (1.12 to 3.12) 41.1
 Newcastle 85+ study 27/109 36/309 2.02 (1.30 to 3.13) 56.3
 TOOTH 1/33 0/64 1.98 (0.25 to 15.53) 2.6
Total (I2 = 0%)    1.95 (1.40 to 2.71) 100.0
  1. Abbreviations: HR Hazard ratio, CI Confidence interval, eGFR Estimated glomerular filtration rate, CRP C-reactive protein
  2. a Iron deficiency was defined as ferritin < 20 μg/L for men, < 15 μg/L for women; vitamin B12 deficiency was < 150 pmol/L; folate deficiency was serum folate level < 7 nmol/L (Leiden 85-plus Study and TOOTH) or < 340 nmol/L (Newcastle 85+ Study); low eGFR was < 45 mL/min/1.73 m2, eGFR was calculated using MDRD (Modification of Diet in Renal Disease) Study equation from the National Kidney Foundation; high CRP was > 5 mg/L
  3. b Results of fully adjusted model (model 3): adjusted for age, sex, institutionalisation, smoking and ≥ 2 multi-morbidity. Multi-morbidity was composed of stroke, coronary heart disease (CHD), cancer and diabetes. It was stratified into 0 to 1 or 2 and above as a binary variable. Leiden 85-plus Study: sex, institutionalisation, smoking and ≥ 2 multi-morbidity [stroke, coronary heart disease (CHD) excluding stroke, cancer, diabetes]; Newcastle 85+ study: age, sex, institutionalisation, smoking, ≥2 multi-morbidity (CVA, combined cardiac disease excluding CVA, cancer, diabetes); TOOTH: age, sex, smoking, ≥2 multi-morbidity (stroke, coronary heart disease (CHD), cancer, diabetes)
  4. c LiLACS NZ did not have follow-up data for hemoglobin; TOOTH: since not all determinants were collected at baseline, 3-year follow-up was defined as baseline, and 6-year follow-up as follow-up data. All three studies included five determinants: iron, vitamin B12, folate deficiency, low eGFR, and high CRP
  5. d Population with determinant within total anemic population during follow-up
  6. e Population with determinant within total non-anemic population during follow-up
  7. f A population size of zero led to an inestimable hazard ratio