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Table 1 Baseline characteristics of randomised participants (n = 300)

From: Clinical and cost-effectiveness of oral sodium bicarbonate therapy for older patients with chronic kidney disease and low-grade acidosis (BiCARB): a pragmatic randomised, double-blind, placebo-controlled trial

 Sodium bicarbonate (n = 152)Placebo (n = 148)
Mean age (years) (SD)73.9 (7.6)74.0 (6.6)
Age 60–64 (%)13 (8.6)13 (8.8)
Age 65–69 (%)44 (28.9)22 (14.9)
Age 70–74 (%)23 (15.1)44 (29.7)
Age 75–79 (%)30 (19.7)37 (25.0)
Age 80–84 (%)32 (21.1)24 (16.2)
Age 85 and over (%)10 (6.6)8 (5.4)
Female sex (%)42 (27.6)44 (29.7)
Ethnicity
 White (%)144 (94.7)143 (96.6)
 East Asian (%)0 (0)1 (0.7)
 Black (%)1 (0.7)0 (0)
 South Asian (%)4 (2.6)2 (1.4)
 Hispanic (%)1 (0.7)0 (0)
 Other (%)2 (1.3)2 (1.4)
Cause of renal dysfunction*
 Hypertension (%)37 (24.3)40 (27.0)
 Diabetes mellitus (%)23 (15.1)23 (15.5)
 Glomerulonephritis (%)9 (5.9)11 (7.4)
 Polycystic kidney disease (%)11 (7.2)9 (6.1)
 Vascular disease (%)19 (12.5)21 (14.2)
 Other (%)52 (34.2)63 (42.6)
 Not known (%)31 (20.4)22 (14.9)
Cardiovascular comorbidity
 Hypertension (%)135 (88.8)129 (87.2)
 Diabetes mellitus (%)54 (35.5)47 (31.8)
 Ischaemic heart disease (%)26 (17.1)31 (20.9)
 Stroke (%)16 (10.5)12 (8.1)
 Heart failure (%)19 (12.5)5 (3.4)
 Peripheral vascular disease (%)14 (9.2)10 (6.8)
Previous fragility fracture (%)2 (1.3)5 (3.4)
Mean number of medications (SD)8.2 (3.7)7.9 (3.3)
Medication use:
 ACEi/ARB (%)105 (69.1)91 (61.5)
 Phosphate binder (%)32 (21.1)28 (18.9)
 Activated vitamin D (%)77 (50.7)73 (49.3)
 Erythropoietin (%)89 (58.6)106 (71.6)
 Iron (%)60 (39.5)51 (34.5)
Mean eGFR (mL/min/1.73 m2) (SD)19.7 (6.5)18.2 (6.4)
CKD category 5 (%)34 (22.4)48 (32.4)
Mean serum bicarbonate (mmol/L) (SD)20.6 (2.6)20.1 (2.5)
Mean haemoglobin (g/L) (SD)115 (14)117 (17)
Mean serum potassium (mmol/L) (SD)4.9 (0.5)4.9 (0.5)
Mean Short physical performance battery (SD)8.0 (2.4)8.1 (2.2)
Mean 6-min walk distance (m) (SD)304 (134)317 (133)
Mean handgrip strength (kg) (SD)
 Males26.6 (8.8)28.0 (7.6)
 Females15.4 (4.8)15.8 (4.4)
Mean body mass index (kg/m2) (SD)28.9 (4.5)28.3 (4.6)
Mean mid-arm muscle circumference (cm) (SD)24.9 (3.6)24.8 (4.0)
Mean triceps skinfold thickness (mm) (SD)16 (8)17 (9)
Mean mid-thigh circumference (cm) (SD)47.4 (7.0)46.8 (7.0)
Mean EQ-5D-3L (SD)0.73 (0.22)0.74 (0.24)
Mean EQ-5D thermometer (SD)69 (19)71 (19)
Mean KDQoL scores
 SF36 PCS (SD)36 (11)36 (11)
 SF36 MCS (SD)53 (11)54 (9)
 Burden (SD)75 (26)75 (25)
 Symptoms (SD)79 (14)81 (12)
 Effects (SD)86 (14)87 (15)
Mean office systolic blood pressure (mmHg) (SD)143 (18)143 (18)
Mean office diastolic blood pressure (mmHg) (SD)75 (11)73 (10)
  1. ACEi angiotensin-converting enzyme inhibitor, ARB angiotensin receptor blocker, CKD chronic kidney disease, KDQOL Kidney Disease Quality of Life questionnaire, SF-36 Short-Form 36-Item questionnaire, PCS physical component summary, MCS mental component summary, EQ-5D EuroQoL 5 dimension quality of life questionnaire
  2. *More than one aetiology possible; thus, values sum to > 100%