Patient Survival by Diabetic Status The presence of diabetes mellitus has a major

31 90 mmHg, a diastolic blood pressure of less than 70 mmHg was associated with a 28 higher risk of death while a diastolic blood pressure of 90-99 mmHg and 100 mmHg or more was associated with a 1.3 and 2.2 times higher mortality risk respectively. The U-shaped relationship has also been reported in other series. [14][15] After adjustment for diastolic blood pressure and other risk factors, systolic blood pressure and pulse pressure did not independently affect mortality. Anaemia was associated with increased mortality and poorer quality of life.[16] A haemoglobin level of less than 8gdl was associated with a 2.2 times higher risk of death compared to a haemoglobin level of 10-12gdl; while a haemoglobin level of 8-10gdl was associated with a 31 increase in mortality. The lowest risk of death was recorded in patients with haemoglobin of 11- 12gdl but this was not statistically significant compared to the reference group haemoglobin 10- 11gdl. There was no significant improvement in survival with haemoglobin level of more than 11gdl. The USRDS data showed that serum phosphate of more than 2.08 mmoll was associated with a 27 increase risk of death.[17] Using a timed average phosphate concentration over 2 years in more than 12,000 patients, Ganesh et al showed that hyperphosphataemia serum phosphate 2.08 mmoll was associated with a 41 risk of death from cardiovascular disease and a 20 risk of sudden death.[18] Our data showed that hyperphosphataemia had a significant impact on death only when serum phosphate was 2.4 mmoll or higher - a serum phosphate level of 2.4 to 2.6 moll resulted in a 71 increase risk of mortality compared to the reference range of 1.6 to 2.0 mmoll. Hypercalcaemia serum calcium 2.6 mmoll or more was associated with a 24 increased risk of death compared to the reference range of 2.2 to 2.6 mmoll in our dialysis population . Foley et al reported that chronic hypocalcaemia was associated with more than two times increased risk of mortality in contrast to our results which did not show any significant increased risk of mortality.[19] The reasons for the discrepancy are unclear. Patients with a low calcium phosphate product less than 3.5 mmol 2 l 2 was associated with a 31 higher risk of mortality when compared to those with normal calcium phosphate product 3.5-4.5 mmol 2 l 2 . High calcium phosphate product did not adversely affect survival. This differs from other series where high calcium phosphate product was also associated with increased mortality.[20] Hepatitis B antigenaemia had no effect on patient survival and this is consistent with other reports.[21] [22] A positive hepatitis C virus HCV antibody also did not confer an increase in risk of mortality. However this differs from experience from other centres where a positive HCV antibody was associated with a higher relative risk of death compared to patients negative for HCV antibody. [23-26] Conclusion In conclusion survival of our dialysis patients over the last 10 years is comparable to those reported from other centresregistries. The reasons for poorer survival in recent years need to be identified and corrective measures implemented. Table 3.6 Adjusted hazard ratio for mortality of dialysis patients 1997-2002 cohort Factors N Hazard ratio 95 CI P value Age years: 0- ≤14ref. 157 1.00 15- ≤24 417 1.82 0.89,3.71 0.100 25- ≤34 727 1.58 0.79,3.16 0.198 35- ≤44 1223 1.97 1.00,3.89 0.049 45- ≤54 1885 3.12 1.60,6.09 0.001 55- ≤64 1907 4.03 2.06,7.89 0.000 ≥65 1094 5.76 2.92,11.33 0.000 Gender: Male ref. 4113 1.00 Female 3297 0.86 0.75, 0.97 0.015 Primary diagnosis: UnknownUncertain ref. 2168 1.00 Diabetes mellitus 2915 2.14 1.81,2.52 0.000 GN SLE 908 1.04 0.79,1.35 0.777 Polycystic kidney 119 1.61 0.99,2.63 0.057 Obstructive Nephropathy 361 1.39 1.05,1.85 0.023 Others 939 1.23 0.98,1.53 0.073 Year start dialysis 1997-8 ref. 1915 1.00 1999-2000 2652 1.21 1.05,1.39 0.009 2001-2002 2843 1.27 1.06,1.53 0.010 Modality: CAPD ref. 1243 1.74 1.51,2.00 0.000 HD 6167 1.00 BMI: 18.5 1080 1.41 1.15,1.74 0.001 18.5-25 3635 1.27 1.10,1.46 0.001 ≥25ref. 1444 1.00 32 Factors N Hazard ratio 95 CI P value Serum albumin gL 30 558 4.36 3.41,5.56 0.000 30-35 1255 2.31 1.91,2.81 0.000 35-40 2861 1.39 1.17,1.64 0.000 ≥ 40ref. 2170 1.00 Serum cholesterol mmoll: 3.2 197 1.45 1.10,1.92 0.010 3.2-5.2 2987 1.00 0.88,1.13 0.996 ≥5.2ref. 2537 1.00 KTV 1 274 1.73 1.23,2.43 0.002 1.0-1.2 898 1.21 0.96,1.51 0.106 1.2-1.4ref. 1439 1.00 1.4-1.6 1422 0.97 0.80,1.18 0.763 1.6 1823 0.84 0.67,1.05 0.126 Diastolic BP: 70 824 1.23 1.01,1.49 0.036 70-80 2193 1.06 0.92,1.22 0.450 80-90ref. 2800 1.00 90-100 1186 1.31 1.09,1.58 0.004 ≥100 270 2.20 1.63,2.98 0.000 Haemoglobin gdl: 8 1610 2.17 1.78,2.64 0.000 8-9 1783 1.31 1.09,1.60 0.005 9-10 1803 1.26 1.04,1.51 0.016 10-11ref. 1112 1.00 11-12 504 0.89 0.68,1.20 0.453 ≥ 12 234 1.14 0.79,1.63 0.487 Serum Calcium mmoll: 2.2 1683 1.04 0.88,1.24 0.636 2.2-2.6ref. 4423 1.00 ≥ 2.6 673 1.24 1.03,1.50 0.022 Calcium Phosphate product 3.5 2130 1.31 1.08,1.59 0.006 3.5-4.5ref. 2335 1.00 4.5-5.5 1460 0.84 0.67,1.05 0.128 ≥ 5.5 813 0.96 0.64,1.43 0.824 Serum Phosphate mmoll 1.6 2645 1.01 0.82,1.25 0.923 1.6-2.0ref. 2218 1.00 2.0-2.2 788 1.17 0.91,1.50 0.213 2.2-2.4 577 1.07 0.77,1.49 0.670 2.4-2.6 329 1.71 1.11,2.61 0.014 ≥ 2.6 414 1.55 0.98,2.45 0.061 HbAsg: Negativeref 6943 1.00 Positive 467 1.11 0.87,1.40 0.407 Anti-HCV: Negativeref 6276 1.00 Positive 1134 0.89 0.76,1.05 0.163 Cardiovascular disease CVD No CVDref 5938 1.00 CVD 1472 1.49 1.30,1.70 0.000 Figure 3.6a Adjusted hazard ratio for mortality of dialysis patients by diastolic blood pressure 1997-2002 cohort 1.23 1.06 1 2.2 1.31 0.5 1 1.5 2 2.5 70 70-79 80-89 90-99 100 Blood pressure mmHg Haza rd r a tio Table 3.6 Adjusted hazard ratio for mortality of dialysis patients 1997-2002 cohort