The Pearson product moment correlation usually denoted as ‘r’ between the electrolytes levels are presented in the upper triangle of Table 1 while the lower triangle shows the probability value for determining significance. A strong positive and significant correlation was observed between creatinine and urea (r = 0.916 and p-value = 0.000) at p-value < 0.01. Potassium was observed to have a weak positive and significant correlation with chloride (r = 0.244 and p-value = 0.029) at p-value < 0.05, creatinine (r = 0.292 and p-value = 0.009) and urea (r = 0.327 and p-value = 0.003) at p-value < 0.01
Table 1
Correlation between the Electrolyte Levels of Malaria Patients
Electrolyte | Na | K | Cl− | HCO3− | C4H9N3O2 | CH4N2O |
Na | 1.000 | -0.011 | 0.139 | 0.163 | -0.030 | -0.032 |
K | 0.926 | 1.000 | 0.244* | 0.142 | 0.292** | 0.327** |
Cl− | 0.219 | 0.029 | 1.000 | -0.016 | -0.014 | 0.077 |
HCO3− | 0.149 | 0.209 | 0.891 | 1.000 | 0.138 | 0.134 |
C4H9N3O2 | 0.792 | 0.009 | 0.900 | 0.222 | 1.000 | 0.916** |
CH4N2O | 0.776 | 0.003 | 0.495 | 0.237 | 0.000 | 1.000 |
Key: SV – Source of Variation Na – Sodium K – Potassium Cl− - Chloride |
HCO3− - Bicarbonate C4H9N3O2 – Creatinine CH4N2O – Urea |
.
The mean bound distribution of the electrolyte levels across all the four categories of malaria patients is presented in Table 2.
Table 2
Mean Statistics of Electrolyte Perturbation in Malaria Patients
Malaria Status | Na | K | Cl− | HCO3− | C4H9N3O2 | CH4N2O |
MP-nil | 132.50 ± 4.37 | 3.64 ± 0.14 | 90.85 ± 1.14 | 25.90 ± 0.82 | 198.55 ± 75.45 | 7.57 ± 2.36 |
MP-(+) | 129.75 ± 1.61 | 3.32 ± 0.16 | 92.05 ± 1.38 | 26.30 ± 0.87 | 95.20 ± 18.08 | 4.61 ± 0.84 |
MP-(++) | 126.25 ± 1.77 | 3.20 ± 0.13 | 89.20 ± 0.98 | 24.75 ± 0.80 | 91.75 ± 9.16 | 4.34 ± 0.86 |
MP-(+++) | 130.20 ± 1.48 | 3.57 ± 0.15 | 91.95 ± 1.22 | 24.95 ± 0.70 | 112.00 ± 22.66 | 6.03 ± 1.28 |
Key: Mean ± Standard Deviation |
The mean bound of patients’ sodium level was observed to fall within the specified normal limits of 125 mmol/L – 145 mmol/L (Table 2), except for positive malaria patients belonging to the MP-(++) which will fall below the 125 mmol/L (i.e. 126.25 mmol/L – 1.77 mmol/L = 124.48 mmol/L). The spread of the sodium data taken from the patients were observed to fall within the normal limits leaving only the boxplot’s lower whisker out, that is, observations falling within the first quartile, except for MP-(++) patients with observations in the first to second quartile spreading outside the normal lower limit (Fig. 2).
The mean bound of patients’ potassium level was observed to fall within the specified normal limits of 2.8 mmol/L – 4.8 mmol/L (Table 2). Almost all the box spread of the potassium data taken from the patients were observed to fall within the normal limits leaving only the lower whisker out, that is, the observations in the first quartile and half of it for the MP-(+++). The case is different for the negative tested patients, the box and its whiskers were almost engulfed within the normal limits (Fig. 3).
The mean bound of the chloride level of MP-(+) and MP-(+++) malaria (positive category) patients’ was observed to fall within the specified normal limits of 90 mmol/L – 115 mmol/L (Table 2). The lower bound of the mean for negatively tested and MP-(++) malaria (positive) patients were observed to fall below the lower limit of 90 mmol/L (i.e. 90.85 mmol/L – 1.14 mmol/L = 89.71 mmol/L and 89.20 mmol/L – 0.98 mmol/L = 88.22 mmol/L) respectively. However, the box spread of the chloride data taken from the patients were observed to fall slightly outside the normal lower limit for negatively tested and positively MP-(+++) tested patients, and about half of the observations falling outside the normal lower limit for positively MP-(+) tested patients. The case is entirely different for positively MP-(++) tested patients, all the observations in the first to the third quartile spreads below the normal lower limit (Fig. 4).
The mean bound of patients’ carbonate level was observed to fall completely within the specified normal limits of 20 mmol/L – 30 mmol/L (Table 2). The spread of the carbonate data taken from the patients were observed to fall within the normal limits except for MP-(+) patients with observations in the fourth quartile region spreading outside the normal upper limit (Fig. 5).
The mean bound of patients’ creatinine level was observed to fall within the specified normal limits of 50 mmol/L – 110 mmol/L for positively MP-(++) tested malaria patients and, outside the specified normal limits for negatively tested and positively MP-(+) tested malaria patients (198.55 mmol/L ± 75.45 mmol/L = 123.10 mmol/L or 274 mmol/L and 95.20 mmol/L ± 18.08 mmol/L = 77.12 mmol/L or 113.38 mmol/L) respectively while the positively MP-(+) tested malaria patients have their upper mean bound (i.e. 112.00 mmol/L + 22.66 mmol/L = 134.66 mmol/L) above the normal upper limit (Table 2). The high variation in the mean bound of the negatively tested patients can be attributed to the greatly distant outliers in the observations (Fig. 5). The spread of the creatinine data taken from the patients were observed to fall within the normal limits except for the MP-(++) patients with observations in the fourth quartile region spreading outside the normal upper limit (Fig. 6).
The mean bound of patients’ urea level was observed to fall within the specified normal limits of 2.0 mmol/L – 8.0 mmol/L (Table 2), except for the negatively tested malaria patients which have the upper bound of their average distribution to be above the 8.0 mmol/L (i.e. 7.57 mmol/L + 2.36 mmol/L = 9.93 mmol/L). The spread of the urea data taken from the patients were observed to fall within the normal limits with each of the categories having at least one outlier; two females tested MP-nil, a male and a female tested MP-(+), a male tested MP-(++) and two males and one female tested MP-(+++) (Fig. 7).
Table 3
Analysis of Variance in the Electrolyte Level of Malaria Patients
SV | Df | Na | K | Cl− | HCO3− | C4H9N3O2 | CH4N2O |
Between Status | 3 | 133.283 | 0.860 | 35.112 | 11.083 | 50470.950 | 44.315 |
Within Status | 76 | 135.049 | 0.413 | 28.311 | 12.720 | 33082.999 | 43.224 |
F (P-Value) | | 0.987 (0.404) | 2.081 (0.110) | 1.240 (0.301) | 0.871 (0.460) | 1.526 (0.215) | 1.025 (0.386) |
Key: SV – Source of Variation Na – Sodium K – Potassium Cl− - Chloride |
HCO3− - Bicarbonate C4H9N3O2 – Creatinine CH4N2O – Urea |
A significantly difference between the four statuses of the malaria patients was not observed from the one way analysis of variance hypothesis test conducted for sodium (F-test = 0.987, P-value = 0.404), potassium (F-test = 2.081, P-value = 0.110), chloride (F-test = 1.240, P-value = 0.301), carbonate (F-test = 0.871, P-value = 0.460), creatinine (F-test = 1.526, P-value = 0.215) and urea (F-test = 1.025, P-value = 0.386) at P-value < 0.05 (Table 3). Although this was expected as the boxplots in Fig. 2–7 overlaps, Fig. 8 further shows the similar variation possessed by the four categories of malaria patients across the six considered electrolyte measures. The distance noticed in the creatinine level for the malaria patients can be attributed to the value of the outliers observed.