3.2 Benchmarks
3.2.2 Machine Learning
STUDY AREA
The study was conducted in Nassarawa LGA of Kano State. Nassarawa LGA is one of the eight LGAs within the metropolitan city of Kano. It was selected by simple balloting. The headquarter is located in Nassarawa GRA, along Bompai road. It has an area of 320 km2. Nassarawa LGA lies between latitudes 11o57I30II N and 12o3I30II N, as well as between longitudes 8032I0II E and 8037I0IIE (Figure 3). Kano city has 2 seasons:79 The wet season occurs between June and September with average rainfall of 19 cm (12 – 31cm), relative humidity of 57% and average temperature of 27oC.79 The dry season runs between October and May. The coolest average temperature is 13oC in December and January while the warmest temperature occurs in April at 38oC.
Nassarawa LGA has a population of 596,669 people and the population growth rate is 3.2%.80 Children aged 10 to 14 years constitute 12% of the population based on available data from national
population commission statistics.81 The inhabitants who are mainly Hausas and Fulanis are predominantly traders and civil servants.
Figure 3: Map of Nassarawa LGA
Adapted with permission from Kano Geographical Information System.
STUDY DESIGN
The study was a prospective cross sectional descriptive study.
STUDY POPULATION
These were pupils aged 10 to 15 years who were drawn from the 43 primary schools82 (18 public and 25 private) and 40 junior secondary schools83 (15 public and 25 private JSS) in the local government. Based on the age of enrolment into school in Kano (five to seven years), children 10 to 12 years of age are mostly found in classes four to six, while those between the ages of 13 to 15 years are in JSS one to three. Children in this age group (10 to 15 years) would comply better with the rules and instructions of two weeks home monitoring,14, 17 hence their selection. The ages of the children were as at their last birthdays as obtained from the school register and from their parents through the study proforma.
STUDY PERIOD
The study was conducted over a period of seven months (March to September, 2012) using 60 peak flow meters which allowed for recruitment of 60 subjects per month.
INCLUSION CRITERIA
These included apparently healthy school children aged 10 to 15 years in Nassarawa LGA of Kano state who gave assent along with their parents’ written consent.
EXCLUSION CRITERIA
• Children with physician diagnosed asthma or history suggestive of asthma.
• Pupils with on-going or preceding acute respiratory infection (ARI) in the past four weeks.
• Children who smoke and children whose parents are smokers.
• Children on medications that are known to affect PEF e.g. bronchodilators.
• Children with obvious cardiac, respiratory or other systemic chronic conditions including sickle cell anemia, mental subnormality and chest wall deformity.
ETHICAL APPROVAL
Institutional approval for the study was obtained from Nassarawa Zonal Education Authority and universal basic education board of Nassarawa LGA. Ethical approval was sought for and obtained from the Ethics Committee of Aminu Kano Teaching Hospital, Kano. Individual assent of the subjects was obtained as well as written consent of their parents or guardians (appendices A, B, E, G & H).
SAMPLE SIZE DETERMINATION:
The sample size was calculated as follows; n
= z2pq where;
d2
n = minimum sample size when population is > 10,000. z = standard normal deviate, set at 1.96 which corresponds to 95% confidence interval. p = the proportion of the target population estimated to have a particular characteristic,
75.9% of the subjects in Oredo LGA, Edo have discernable pattern of PEFvar.29
q = complementary probability to p = 1 − p d = desired precision = 0.05 or 5% level Thus, n = (1.96)2 x 0.759 x (1 – 0.759)
(0.05)2 n = 3.8416 x 0.759 x 0.241
0.0025 n = 281
A contingency of 15% was added to accommodate for non-response/ incomplete response. Thus, 330 subjects were recruited.
SUBJECTS SELECTION
The 330 subjects were selected using a multistage sampling technique from the 43 primary schools (18 public and 25 private schools) and 40 schools with junior secondary school facilities
(15 public and 25 private schools) in Nassarawa LGA. The primary schools were mixed schools.
Among the 15 public secondary schools, nine were all boys’ schools and six were all girls’ schools.
The private junior schools consisted of 10 all boys’ and 15 all girls’ schools. When dealing with a large population that cannot all be sampled, 25% (one-fourth) of that population can be taken as representative of the entire population as this displays the statistical properties of that population.84 Thus, 25% of the number of primary and junior secondary schools in Nassarawa LGA was used (i.e. 20 schools).
Stage 1 (school selection)
Of the 20 schools, using proportionate representation of ratio 43:40 ≈ 1:1, thus 10 primary and 10 secondary schools were selected. The ten primary schools were also sampled using proportionate ratio of 18 public: 25 private ≈ 3:4. Therefore, four public and six private primary schools were selected. The 10 junior secondary schools were also sampled using the same principle i.e. 15 public:
25 private = 3:5, thus four public and six private junior secondary schools were chosen. Similarly, the proportionate ratio sampling was applied to the all boys’ and all girls’ schools (both private and public), thus four all Boys’ and six all Girls’ schools were selected.
With the help of the list of public and private primary schools in Nassarawa emanating from the State Universal Basic Education Board Nassarawa LGA,82 and that of secondary schools in
Nassarawa Zonal Education Board obtained from the Department of Planning & Statistics of Kano State Ministry of Education,83 the names of the schools were stratified into public and private primary schools, public and private boys’ and girls’ junior schools respectively and arranged alphabetically and assigned numbers. The number assigned to each school was written on a small piece of paper, all of equal sizes and folded until the numbers written on them were no longer visible. By balloting, 10 schools were chosen from the primary schools. For the secondary schools, the four boys’ schools were balloted two each from public and private schools while the six girls’
schools consisted of two public and four private schools.
Stage 2 (subject selection)
The 330 subjects were proportionately recruited from the 20 selected schools, based on the population of pupils in each school. The number of pupils to be selected from each school was determined as follows;
No of pupils required from primary school 1(P1) = No of pupils in P1 x 330
Total No of pupils in 1 the 20 selected schools
Table I: Distribution of selected schools and the number of pupils selected from each school
S/N Name of the School Code class population Number of Subjects Selected
1 Race Course Primary School P1 380 18
2 Hassan Gwarzo Islamic School P2 317 15
3 Hotoro South Primary School P3 403 19
4 Kawaji-Yankaba Primary School P4 382 18
5 Global Academy Dakata P5 340 16
6 Rainbow Primary School P6 275 13
7 Gwagwarwa Primary School P7 425 20
8 Kano Model Primary School P8 405 19
9 Basic Foundation Primary School P9 322 15
10 Gateway International Primary School P10 256 12
11 Kano Capital Boys School B1 437 20
12 Ahamadiyya Boys Secondary School B2 405 19
13 G.S.S. Kawaji B3 512 24
14 Sepherd Academy B4 385 18
15 Kano Capital Girls School G1 375 18
16 Nana Khadija Secondary School G2 210 10
17 G.G.S.S. Dakata G3 340 16
18 G.G.S.S. Magwan G4 340 16
19 St Louis Secondary School G5 250 12
20 Khadija Islamic Secondary School G6 256 12
7005 330
TOTAL Prim=3505, JSS=3500 *Prim=165, ΔJSS=165
JSS = Junior Secondary School, Prim = Primary School
G.G.S.S. = Government Girls Secondary School G.S.S. = Government Secondary School
* = No of pupils selected from primary schools
Δ = No of pupils selected from junior secondary schools
Using the class registers, and with the assistance of the class teachers, the pupils in all arms of the various classes (Primary 4 – 6 / JSS1 - 3) were grouped together. The number to be sampled from each school was shared among classes 4 – 6 or 1 - 3 proportionately based on the population of each class. For instance, there were 134 pupils in all arms of class 4 of P1, and total number of pupils in P1 = 380, and P1 was to produce 18 subjects for the study, then, the number of pupils selected from class 4 of P1 = 134 x 18 = 6.
380
Then, the grouped classes were stratified on the basis of age and then gender in case of Primary 4 – 6. For example, there were 60 pupils in age cohort 10 years in class 4 of P1 which was expected to produce 6 subjects, then, age cohort 10 years of class 4 proportionately accounted for 60 x 6 = 3.
134
The three pupils in the 10 year age group of class 4 of P1 were chosen from the two gender cohort proportionately. Since there were 40 boys and 20 girls in the group, then, the number of boys selected = 40 x 3 = 2.
60
Therefore, two boys and one girl were picked from the gender cohorts in the age group 10 years of class 4 of P1. The sampling interval (K) for the study was calculated as:
K = Total No of pupils in the 20 selected schools = 7005 = 21 Calculated sample size 330
A sampling frame (list of names of the subjects based on age cohort and gender in alphabetical order) for each class group was drafted with the help of the class teachers. A die was tossed to determine the starting point of the systematic sampling and thereafter every twenty-first eligible subject was selected. On occasion where the subject selected did not meet the inclusion criteria of the study, the process was repeated to replace such a subject. These steps were repeated for other age and/ or gender cohorts of the classes of all the schools until a total of 330 subjects were recruited. The entire process is shown by the flow charts in Figures 4 and 5.
Figure 4; Flow chart of the multi-stage sampling technique used in primary schools.
25 % of the 43 schs was taken as representative of NSR Primarypupils
18 Public & 25 private
Primary schools
4 Public & 6 Private primary schools were sampled
Race Course Model PrimarySchool(P1) Hassan Gwarzo Islamic Primary School (P6) Hotoro South PrimarySchool(P2) Kawaji-Yankaba Primary School (P7) Global Academy PrimarySchoolDakata(P3) Rainbow School (P8)
Gwagwarwa PrimarySchool(P4) Kano Model Nursery & Primary School (P9) Basic Foundation PrimarySchool(P5) Gateway International School (P10)
No pupils selected from P1=No of pupils inclass 4-6 ofP1 x No pupils selected from prim schs (165) = 18 No pupils in classes 4-6 of the 10 schools 1
No pupils selected from class 4= No pupils in all arms of class 4 x No pupils selected from P1= 6 No pupils in class 4-6 of P1
No pupils age 10yrs selected from class 4 = No pupils in age cohort 10yrs x No pupilsselected from class 4 = 3 No pupils in class 4
No male selected from 10yr age grp of class 4 = No boys in10yr age grp of class 4 x No 10yr pupils selected = 2 No pupils in 10yr age grp of class 4
By Balloting
Proportionate samplingto select pupils from each sch e.g. P1
Proportionate samplingto select pupils from each class e.g. class 4of P1
Proportionate samplingto select pupils in each age group e.g.10yr age cohort of class 4of P1
Proportionate samplingto select male pupils from each age cohort e.g. 10yr age grpof class 4of P1
Figure 5; Flow chart of the multi-stage sampling technique used in junior secondary schools MATERIALS
Peak Expiratory Flow was determined using a mini-Wright peak flow meter (Clement Clarke, England). It was calibrated in Litre per minute (Figure 6). Each subject used a single plastic mouth piece and no nose clip was used.
Figure 6: Clement Clarke Mini-Wright peak flow meter.85 The weight of the subjects was measured using a well calibrated bathroom weighing scale (UMEC, model 98114). The scale had a sensitivity of 0.1kg (100g) and was re-calibrated weekly with a known weight.
The height of the pupils was measured using a stadiometer (model Accustat, Ross, Germany), calibrated up to two meters and reading to the nearest 0.1cm.
A simple proforma was used to obtain information about the subjects; including age as at last birthday, socioeconomic background, domestic exposure to smoke, past and present medical
history. The part A of the proforma was filled by the parents/ guardians along with their consent forms. The proforma was pre-tested on a sample of 30 pupils of Bright academy primary school in Tarauni LGA of Kano state. Following observation from the pre-test, the timing of PEF measurement was adjusted to 7 a.m., 3 p.m. and 9 p.m. instead of the proposed 6 a.m., 2 p.m. and 10 p.m. to improve compliance as many respondents complained about the time of the measurement and 40% timing mis-compliance was observed. Little modification was done to the part B of the proforma to include asking the subjects about cigarette smoking as their parents may not know especially in the older children.
A record book specifically designed for the recording of peak expiratory flow measurement was given to each subject.
PROCEDURE
The selected subjects were examined by the researcher and/ or his assistants (two residents who had undergone training on peak flow measurement based on manufacturer’s note to clients). The weight of the subjects was measured by the researcher and/ or his assistants in the presence of their teachers. Each subject was weighed without shoes and wearing only one layer of light cloth. The scale was checked for zero adjustment before weighing each subject. The weight was recorded to the nearest 100g.
The height was determined by the researcher and/ or his assistants using standard technique described by Paynter and Parkin.86 Each subject was asked to stand barefooted with his/ her heels, buttocks, shoulders and occiput against the perpendicular part of the stadiometer, and look straight such that the subject’s ear holes lie on the same horizontal plain as the lower border of his/ her eye
sockets (Frankfurt plane), then the head rest was brought to rest on the head of the subject and the pointer was read. The height of the subjects was recorded in centimeters to the nearest 0.1cm.
Subjects were trained on, and familiarized with, the use of PFM over a three day period, in a group of fives, in the school laboratory or conference/ assembly hall. The technique of PEF measurement was in accordance with manufacturer’s instructions. Each subject was required to hold the PFM lightly and horizontally while standing erect and ensure that his/her fingers did not restrict movement of the pointer and the vents of the meter (Figure 7).
The empty mouth of the subject was opened to allow a deep slow breath to be taken and the lips were then firmly applied around the mouth piece, and the subject blew as hard and as fast as possible into the mouth piece with the force coming from the chest and not the cheeks or by coughing. The pointer was read on the scale in L/min and it was then returned to the lower end of the scale before the next measurement.
The pupils were given free access to practice the manoeuvre. On the 3rd day of the training, a mock recording of PEF was conducted to ascertain their understanding of the procedure. Pupils were certified competent when they achieved reproducibility within 20 L/ min of successive manoeuvres.59 Those who could not comply were retrained for another two days after which if they fail to perform, they were replaced by new subjects recruited using the procedure described earlier.
Following this, each subject was given a PFM to take home. They were asked to perform PEF measurement (strictly on standing) three times a day i.e. at 7 a.m., at 3 p.m., and at 9 p.m..
Mothers or guardians were instructed to ensure the PEF measurements and recordings were done within 15 minutes of the stipulated time. At each measurement, the manoeuvre was repeated three
times. The three readings were recorded and the best of the three readings was taken as the PEF for the time. The subjects were requested to bring these record books to the school daily for inspection by the researcher or his trained assistant (one of the class teachers in each school had training on peak flow measurement and recording) to ensure proper recordings.
The PEF was measured three times daily for 18 days out of which the first 14 completed days were selected. The record books and PFM were collected from the subjects (at the completion of the exercise) and the mouth piece disposed. Sixty peak flow meters were used for the exercise.
Figure 7: A pupil using the mini peak flow meter.
Calculation of mean PEF & PEFvar
The mean PEF was calculated from the individual mean of the day obtained from the three PEF recordings and then averaged over the first 14 completed recording days as shown below;
Individual daily mean PEF = 7 a.m. PEF + 3 p.m. PEF + 7 p.m. PEF 3
Individual mean PEF = Sum of the daily mean PEFs over the first 14 complete recording days 14
Overall/ study mean PEF = Sum of individual mean PEFs of all the 310 subjects
310
While PEFvar expressed as amp % of the mean was calculated from highest PEF of the daily measurement minus the lowest divided by the day’s mean multiplied by hundred, then averaged over the first 14 completed recording days as follows;
Individual daily PEFvar = highest PEF – lowest PEF of that particular day × 100 Mean PEF of that day 1
Individual mean PEFvar = Sum of the individual PEFvars of the 1st 14 completed recording day 14
Study mean PEFvar = Sum of the individual mean PEFvars of all the 310 subjects 310
Categorization of Weight and Height of the subjects
The World Health Organization (WHO) growth charts were used to categorize the height and weight of the subjects (appendix ).
Under-weight = weight below the 3rd percentile for age and sex
Normal weight = weight between the 3rd and 97th percentile for age and sex Over-weight = weight above the 97th percentile for age and sex
Stunting = Height below the 3rd percentile for age and sex
Normal height = height between the 3rd and 97th percentile for age and sex Tall-stature
= height above the 75th percentile for age and sex
STANDARDISATION OF TOOLS
At the beginning of the study, the researcher’s PEF was determined. And at the end of each three week session by a group of subjects, the researcher measured his PEF using each the PFM used by the group and the result were compared to the one he obtained at the beginning of the study.
Any meter found to be producing inconsistent result was withdrawn from the next session.
DATA ANALYSIS
Data was entered into excel spreadsheet for cleaning and subsequently transferred into Minitab12 and Statistical Package for Social Sciences (SPSS) version 16 for analysis. Quantitative variables were analyzed using measures of central tendency (mean) and dispersion (standard deviation, range). Inter group comparison of means were done using student’s t-test while comparison of three or more means were done using statistical test for ANOVA (F-test). The alpha level was set at 0.05.
The correlation of PEF and PEFvar with age, height and weight were assessed using Pearson’s correlation coefficient. The Linear regression analysis was used to draw the graphs and derive the predictive equations. The graphs were drawn using STATA version 12.
RESULTS
Three hundred and ten (93.9%) subjects out of the 330 pupils studied completed their PEF recordings and were subsequently analysed. This consisted of 153 (49.4%) males and 157 (50.6%) females, giving a male to female ratio of about 1 : 1. The distribution of the subjects by gender in the various age groups is shown in Table II.
Table II: Age and sex distribution of the subjects
Age (Years)
Male n (%)
Female n (%)
Total n (%) 10
26
(17.0) 25
(15.9) 51
(16.5) 11
26
(17.0) 27
(17.2) 53 (17.1) 12 29 (19.0) 24 (15.3) 53 (17.1)
13
23
(15.0) 30
(19.1)
53
(17.1)
14 24 (15.7) 27 (17.2) 51 (16.5)
15
25
(16.3) 24
(15.3) 49
(15.7)
Total 153 (100) 157 (100) 310 (100)
The remaining 20 (6.1%) subjects were excluded due to incomplete data. Their characteristics are shown in Table III.
Table III: Demographic characteristics of the excluded pupils
School Age Weight (mean ± SD) kg Height (mean ± SD) cm No of Pupils
Type (years) Male (M) Female (F) Male (M) Female (F) M F
Primary 10 29.9 ± 4.1 31.4 ± 4.7 136.1 ± 3.6 134.3 ± 4.2 2 2 Primary 11 32.0 ± 2.2 34.7 ± 0.0 142.3 ± 4.3 146.4 ± 0.0 2 1 Primary 12 36.1 ± 5.3 36.7 ± 4.2 149.5 ± 2.8 150.7 ± 2.7 2 2 Secondary 13 37.2 ± 1.5 00.0 ± 0.0 154.6 ± 6.1 00.0 ± 0.0 3 0 Secondary 14 42.4 ± 0.0 45.7 ± 0.0 162.1 ± 0.0 160.9 ± 0.0 1 1 Secondary 15 49.6 ± 4.0 48.5 ± 4.5 166.2 ± 6.9 163.1 ± 3.2 2 2
Total No 12 8
The respondents’ ages ranged between 10.0 – 15.0 years with a mean ± SD of 12.5 ± 1.7 years.
Males had a mean ± SD age of 12.4 ± 1.7 years which was comparable to that of females of 12.5 ± 1.7 years, (p = 0.76).
The mean ± SD weight of all subjects was 39.8 ± 9.2 kg with a range of 21.0 – 65.0 kg. Table IVa showed that the mean ± SD weight of males of 38.7 ± 8.4 kg was significantly lower than that of their female counterpart of 40.9 ± 9.2 kg, (p = 0.03).
The mean ± SD height of all the subjects was 152.3 ± 13.0 cm with a range 112.0 – 178.0 cm. The mean ± SD height of males of 151.9 ± 13.0 cm was comparable to 152.7 ± 13.0 cm of their females counterpart as shown in Table IVb, (p = 0.61).
Table IVa: Distribution of Weight of the Subjects by Age and Gender
Age (years) Male weight (mean ± SD) kg Female weight (mean ± SD) kg
10 30.6 ± 3.7 32.6 ± 5.2
11 32.9 ± 4.1 35.4 ± 4.8
12 36.3 ± 7.2 37.8 ± 7.7
13 37.4 ± 4.8 42.9 ± 6.4
14 44.0 ± 7.0 46.8 ± 7.5
15 50.9 ± 4.5 49.7 ± 8.4
Overall Mean 38.7 ± 8.4 40.9 ± 9.4
Table IVb: Distribution of Height of the Subjects by Age and Gender
Age (years) Male height (mean ± SD) cm Female h eight (mean ± SD) cm
10 137.2 ± 9.9 137.8 ± 7.3
11 141.8 ± 7.8 145.2 ± 10.0
12 148.1 ± 8.4 151.3 ± 8.3
13 155.7 ± 6.9 156.9 ± 7.7
14 162.6 ± 6.9 161.0 ± 7.1
15 165.8 ± 6.3 163.8 ± 6.1
Overall Mean 151.9 ± 13.0 152.7 ± 13.0
PEF AND TIME OF MEASUREMENT
Table V shows the distribution of mean and range of PEF of the subjects at various time of the day according to gender.
Table V: Distribution of Peak Expiratory Flow of the subjects and time of measurement
Age Male PEF (mean and range) L/ min (yrs)
10
7 a.m. mean 7 a.m. range 3 p.m. mean 3 p.m.
range
9 p.m. mean 9 p.m. range
327.3 ± 12.5 300 – 360 360.4 ± 16.6 330 – 400 344.2 ± 17.2 310 – 380
11 338.9 ± 20.3 310 – 360 367.7 ± 13.9 350 – 400 359.2 ± 16.2 330 – 420
12 360.3 ± 26.3 320 – 410 385.9 ± 25.7 350 – 460 373.1 ± 27.8 330 – 450
13 359.1 ± 26.4
320 – 410 388.3 ± 27.1 350 – 440 376.1 ± 24.6 330 – 420
14 389.2 ± 29.3 330 – 460 414.2 ± 29.0 360 – 470 403.8 ± 29.6 340 – 450
15 421.2 ± 28.9 380 – 460 446.4 ± 18.7 410 – 490
435.6 ± 22.9
390 – 470
Age (yrs)
Female PEF ( mean and range) L/ min
10
7 a.m. mean 7 a.m. range 3 p.m. mean 3 p.m.
range
9 p.m. mean 9 p.m. range
330.4 ± 17.2 290 – 370 362.4 ± 18.1 330 – 400 345.2 ± 17.4 310 – 380
11 347.4± 20.3 290 – 400 376.3 ± 18.2 330 – 410 361.5 ± 19.6 310 – 410
12 359.1 ± 26.7 290 – 400 387.9 ± 28.0 330 – 450 376.7 ± 28.4 300 – 430
13 383.0 ± 26.8
330 – 430 414.0 ± 26.2 360 – 460 396.0 ± 26.3 340 – 440
14 401.9 ± 27.0 340 – 450 428.2 ± 27.0 380 – 470 416.7 ±26.2 360 – 460
15 410.8 ± 28.3 350 – 450 436.3 ± 26.5 390 – 480 425.8 ±29.3 360 – 480
PEF, GENDER AND AGE
The mean ± SD PEF of all subjects was 398.5 ± 36.1 L/ min. Males had a mean ± SD PEF of 394.6 ± 36.3 L/ min and is comparable to 402.4 ± 35.5 L/ min for females, (p = 0.06). The mean PEF increased progressively in both genders with increasing age (p < 0.001) as shown in Table VI and Figure 8.
Table VI: Peak Expiratory Flow, Gender and Age of the subjects
Age (years) PEF (Mean ± SD) L/ min
Male Female
No of pupils
10
361.2 ± 17.1
363.6 ± 18.0
51
11
371.5 ± 12.6 378.5 ± 16.3 53
12
387.6 ± 26.0 390.4 ± 27.7 53
13 388.3 ± 27.7 414.0 ± 26.2 53
14
415.0 ± 28.7 428.5 ± 26.6 51
15 447.6 ± 19.2 437.5 ± 27.4 49
F 49.24 37.27
p value 0.001* 0.001*
* = Statistically significant, F = Statistical test for ANOVA
The mean PEF shows a linear relationship with age as depicted in Figure 8, given a strong positive correlation between the mean PEF and the age of the subjects (r = 0.746, p ˂ 0.001).
Figure 8: Correlation of Peak Expiratory Flow with Age of the subjects
PEF, HEIGHT AND WEIGHT
The subjects with normal weight had a mean PEF of 399.9 ± 35.2 L/ min, which is higher than those of underweight and overweight subjects, but the differences were not statistically significant (Table VII). In contrast, subjects with normal height had mean PEF of 398.0 ± 36.0 L/ min which is lower than that of subjects with height less than the 95th percentile (405.9 ± 34.2 L/ min), although not statistically significant (p = 0.52).
PEF = 200.0 + 15.9Age
Table VII: Peak Expiratory Flow, Height and Weight of the subjects
Variables No of subjects PEF (mean ± SD) L/min F test df p value
Weight for age
Underweight 77 395.8 ± 36.7
Normal weight 206 399.9 ± 35.2
Overweight
Height for Age
27 395.9 ± 41.1 0.42
2 0.66
Stunting 27 405.9 ± 34.2
Normal Height 265 398.0 ± 36.0
Tall Stature 18 395.6 ± 40.8 0.66 2 0.52
F = Statistical test for ANOVA, df = degrees of freedom, SD = Standard Deviation