The sociodemographic characteristics of the study participants were collected
using a structured interviewer-administered questionnaire. Anthropometric
measurements of the participants, height (cm), weight (kg), waist circumference
(cm), body mass index (BMI), xipho-pubic distance (cm), and abdominal volume
were rigorously evaluated. Height was measured by a stadiometer and weight with
a standard beam balance scale (digital). Waist circumference was got at the
midpoint between the lowest rib and the iliac crest using a tape meter. We
calculated BMI as body weight (kilograms) divided by body height (meters)
squared. Body surface area (BSA) was calculated according to the Mosteller
formula: BSA (m2) = square root of ([Height (cm) × Weight (kg)] /
3600).16 (link) The abdominal volume was computed according to the
standard formula: (waist Circumference / 6.28)2 × xipho-pubic
distance × 3.14.17 All anthropometric measurements were taken by 3 trained
data collectors.
Sonographic evaluation: Kidney measurements were performed in a lateral decubitus
position using a curvilinear probe. All measurements of kidneys were made during
quiet breathing in younger children and in older children, measurements were
made while they were holding their breath. The kidney was identified as having a
brightly echogenic renal capsule with a central (sinus) echogenicity. The
superior and inferior poles were identified and marked in the longitudinal scan
of the kidney; the renal length was taken as the longest distance between the
poles using an electronic caliper. The thickness was measured on the
longitudinal scan, and the maximum distance between the anterior and posterior
walls at the mid-third of the kidney was taken as thickness. The renal width (W)
was measured on the transverse scan, and the maximum transverse diameter was
taken at the hilum as the renal width. Scanning was conducted 3 times, and the
average dimension was taken by the same professionals. Intra-rater reliability
was assessed for the longitudinal dimension and volume of both kidneys.
Accordingly, intra-rater reliability of the length of the right kidney was
0.921, 0.901, and 0.93; and for the volume of the right kidney was 0.911, 0.90,
and 0.901 in Debre Markos comprehensive specialized hospital, Finote Selam
general hospital, and Bichena primary hospitals, respectively. Intra-rater
reliability of volume of the right kidney was 0.923, 0.922, and 0.900; and for
the left kidney was 0.901, 0.913, 0.933 in Debre Markos comprehensive
specialized hospital, Finote Selam general hospital, and Bichena primary
hospitals, respectively. Due to the lack of radiography professionals, repeated
measurements were conducted by the same professional although it would have been
better if measurements were recorded by different professionals. The volume of
the kidney was calculated using the prolated ellipsoid formula (Length × Width ×
Thickness × 0.523).18
using a structured interviewer-administered questionnaire. Anthropometric
measurements of the participants, height (cm), weight (kg), waist circumference
(cm), body mass index (BMI), xipho-pubic distance (cm), and abdominal volume
were rigorously evaluated. Height was measured by a stadiometer and weight with
a standard beam balance scale (digital). Waist circumference was got at the
midpoint between the lowest rib and the iliac crest using a tape meter. We
calculated BMI as body weight (kilograms) divided by body height (meters)
squared. Body surface area (BSA) was calculated according to the Mosteller
formula: BSA (m2) = square root of ([Height (cm) × Weight (kg)] /
3600).16 (link) The abdominal volume was computed according to the
standard formula: (waist Circumference / 6.28)2 × xipho-pubic
distance × 3.14.17 All anthropometric measurements were taken by 3 trained
data collectors.
Sonographic evaluation: Kidney measurements were performed in a lateral decubitus
position using a curvilinear probe. All measurements of kidneys were made during
quiet breathing in younger children and in older children, measurements were
made while they were holding their breath. The kidney was identified as having a
brightly echogenic renal capsule with a central (sinus) echogenicity. The
superior and inferior poles were identified and marked in the longitudinal scan
of the kidney; the renal length was taken as the longest distance between the
poles using an electronic caliper. The thickness was measured on the
longitudinal scan, and the maximum distance between the anterior and posterior
walls at the mid-third of the kidney was taken as thickness. The renal width (W)
was measured on the transverse scan, and the maximum transverse diameter was
taken at the hilum as the renal width. Scanning was conducted 3 times, and the
average dimension was taken by the same professionals. Intra-rater reliability
was assessed for the longitudinal dimension and volume of both kidneys.
Accordingly, intra-rater reliability of the length of the right kidney was
0.921, 0.901, and 0.93; and for the volume of the right kidney was 0.911, 0.90,
and 0.901 in Debre Markos comprehensive specialized hospital, Finote Selam
general hospital, and Bichena primary hospitals, respectively. Intra-rater
reliability of volume of the right kidney was 0.923, 0.922, and 0.900; and for
the left kidney was 0.901, 0.913, 0.933 in Debre Markos comprehensive
specialized hospital, Finote Selam general hospital, and Bichena primary
hospitals, respectively. Due to the lack of radiography professionals, repeated
measurements were conducted by the same professional although it would have been
better if measurements were recorded by different professionals. The volume of
the kidney was calculated using the prolated ellipsoid formula (Length × Width ×
Thickness × 0.523).18
