Table 3.
Comparison of estimative dietary equations and urinary measures of net endogenous acid production, potential renal acid load, and single determinants of net acid excretion (sulphate, phosphate, potassium, magnesium, calcium, and organic acids)a,b
| Methods compared | Bland–Altman analysis |
|||
|---|---|---|---|---|
| Methodology | Bias (95% CI) | Lower limit of agreement (95% CI) | Upper limit of agreement (95% CI) | |
| UNEAP vs. NAE, mEq/d | Standard | –2 (–8, 3) | –32 (–46, –24) | 28 (20, 41) |
| NEAPR vs. NAE, mEq/d | Nonparametric | –2 (–15, 5) | –25 (–27, –20) | 16 (13, 16) |
| NEAPF vs. NAE, mEq/d | Standard | 19 (13, 25) | –14 (–27, –6) | 51 (44, 65) |
| NEAPL vs. NAE, mEq/d | Standard | 2 (–3, 7) | –27 (–40, –20) | 31 (24, 43) |
| NEAPS vs. NAE, mEq/d | Standard | –22 (–27, –16) | –51 (–64, –44) | 8 (1, 20) |
| NEAPR vs. UNEAP, mEq/d | Standard | –1 (–6, 3) | –25 (–36, –18) | 22 (15, 33) |
| NEAPF vs. UNEAP, mEq/d | Standard | 21 (16, 27) | –10 (–24, –3) | 53 (46, 67) |
| NEAPL vs. UNEAP, mEq/d | Standard | 4 (–1, 9) | –23 (–34, –16) | 31 (25, 43) |
| NEAPS vs. UNEAP, mEq/d | Standard | –19 (–24, –15) | –47 (–58, –40) | 8 (1, 19) |
| PRAL vs. UPRAL, mEq/d | Standard | 20 (16, 24) | –3 (–14, 3) | 43 (36, 54) |
| PRALS vs. UPRAL, mEq/d | Standard | –4 (–8, 0) | –26 (–36, –20) | 18 (12, 29) |
| OAdiet vs. OAurine, mEq/d | Nonparametric | –15 (–19, –11) | –25 (–27, –23) | –5 (–8, 5) |
| OAanthro vs. OAurine, mEq/d | Standard | –21 (–23, –19) | –32 (–37, –29) | –10 (–13, –5) |
| Sulphatedietc vs, Sulphateurine, mEq/d | Nonparametric | –7 (–8, –4) | –11 (–11, –9) | 0 (–3, 0) |
| Proteindietd v Sulphateurine, mEq/d | Nonparametric | 16 (14, 21) | 11 (10, 12) | 26 (23, 27) |
| Phosphorusdietc vs. Phosphorusurine, mEq/d | Standard | –30 (–32, –27) | –44 (–51, –40) | –15 (–19, –8) |
| Potassiumdietc vs. Potassiumurine, mEq/d | Standard | –6 (–9, –3) | –23 (–31, –18) | 12 (7, 19) |
| Magnesiumdietc vs. Magnesiumurine, mEq/d | Standard | –12 (–13, –11) | –17 (–20, –15) | –7 (–9, –5) |
| Calciumdietc vs. Calciumurine, mEq/d | Standard | –14 (–17, –11) | –33 (–43, –27) | 5 (–1, 15) |
NAE, net acid excretion; NEAP, net endogenous acid production estimated by dietary records where NEAPR pertains to the equation by Remer and Manz,7 NEAPF to the equation by Frassetto et al.,6 NEAPL to a model attributed to Lemann,11, 12, 13 and NEAPS to the equation by Sebastian et al.9; PRAL, potential renal acid load estimated by dietary intake where PRAL is the equation by Remer and Manz,7 and PRALS pertains to the equation by Sebastian et al.9UNEAP, net endogenous acid production determined by urine analysis; UPRAL, potential renal acid load determined by urine analysis; OA, organic acids where OAanthro pertains to the anthropometrical estimate by Manz et al.,10 and OAdiet to the estimative equation by Kleinman and Lemann.11
The bias indicates the extent to which the first method listed in the methods column, under (negative values) or over (positive values) estimates the second method listed and so on.
ll participants were used in all analyses and no data points were removed.
Adjusted for intestinal absorption using multipliers specified in PRALS.
Adjusted for intestinal absorption using multipliers specified in PRAL.