Multivariable-adjusted associations between quartiles of time-averaged serum ALP and serum PTH and all-cause mortality. Patients in the first quartiles served as the reference group. Multivariable models were adjusted for age, race, comorbidities, blood pressure, BMI, smoking status, medication use, enrolment period, estimated GFR, serum albumin, bicarbonate, AST, ALT, calcium, phosphorus, blood haemoglobin, WBC, percentage of lymphocytes in WBC and 24-h urine protein.