Study setting and study period
The study was conducted in the southwest showa zone, Oromia, Ethiopia from May 6 to July 20, 2022, using records of patients following up on their treatment for 6 months in health facilities from January 2017 to December 2021.
Study participants
Participants with tuberculosis disease were recruited from 16 randomly selected health facilities in the southwest showa zone of Oromia, Ethiopia. Participants with a Z-score <-2 (<-2-Z-score) were classified as malnourished, and participants with a Z-score > = -2 (>=-2-Z-score) were classified as well-nourished. All participants were treated according to the national guideline for TB treatment (WHO) [21], with 2 months RHZ+E or RHZE and 4 months RH. A total of 451 children with TB were registered for TB treatment at the selected health facilities. Of those, 258 children with TB were randomly selected. About 16 (6.2%) 1-year TB, 119 (46.1%) of the 1–10-year group, and 123 (47.7%) of the 11–15-year group as shown in figure 1 below.
Study Design
An institutional-based retrospective cohort study was conducted in Southwest showa (SWS) at selected health facilities.
Populations
Source population
All records of Children diagnosed with tuberculosis that have been on anti-TB treatment for at least 6 months and are aged 6 months to 15 years in SWS during the study period.
Study population
All randomly selected records of Children diagnosed with tuberculosis who have been on anti-TB treatment for at least 6 months and are aged 6 months to 15 years of selected health facilities in SWS from January 2017 to December 2021.
Inclusion and exclusion criteria
All records of children aged 6 months to 15 years and treated for TB at the health facilities of the SWS zone were enrolled during the study period. Full patient data, new case PTB/EPTB, and re-treatment cases are included in this study. As exclusion criteria, no documented treatment outcome, MDR TB, the patient who was treated for longer than 6 months was excluded.
Sample size and Sampling Procedure
Sample Size Determination
The total sample size of nutritional status and TB treatment outcomes among children required for this study was determined by calculating the first and second specific objectives separately, and the largest sample size is taken.
Based on the above concept, a study done in the Democratic Republic of Congo, the estimated proportion of TB treatment outcome (success) among well-nourished children would occur at 44.7% (P1 = 0.447) [38] and 23.52% estimated proportion of TB treatment outcome (success) among malnourished, (P2 = 0.235) An estimated 2:1 ratio well-nourished to malnourished was used. Zβ= Probability that malnourished and well-nourished children on TB treatment produced a significant difference and the power =80% and Zß=0.84, Zα= 95% confidence level, and Zα = 1.96, 10% = the non-response rate, loss to follow up 5%.
Hence,
By adding a non-response rate of 10%, and loss to follow of 5% the sample size was 75+7.5+3.75 =86
Therefore, 86 estimated numbers of malnourished and 172 well-nourished children among children on TB treatment, and the total number of study children on TB in the two groups is 258.
Sampling technique
The source population was all records of children aged 6 months to 15 years with TB on daily DOTS at the SWS zone health facilities from January 1/2017 to December 30/2021[23]. The total number of children on TB treatment in public health facilities in the SWS zone is 1154, treated in 54 health centers and 6 hospitals. From 54 health centers and 6 hospitals provide daily DOTS (Lukas and Tulu bolo) and 14 health centers are selected by computer-generated simple random sampling. A systematic technique was employed to select nutritional status and TB treatment outcome among children on TB treatment separately after determining K-value, from the sampling frame (medical registration number).
Proportionally allocated to each selected health facility based on the following formula and showed table 1 below.
Table 1: proportionally allocated to each selected health facility
s/no
|
Health facilities
|
P/allocation
|
Well-nourished
|
Malnutrition
|
total
|
1
|
Lukas GH
|
86*258 /451
|
33
|
16
|
49
|
2
|
Tulu bolo GH
|
72*258/451
|
27
|
14
|
41
|
3
|
Leman HC
|
30*258/451
|
11
|
6
|
17
|
4
|
Tare HC
|
27*258/451
|
10
|
5
|
15
|
5
|
Gibiso HC
|
24*258/451
|
9
|
5
|
14
|
6
|
Tulu bolo HC
|
35*258/451
|
13
|
7
|
20
|
7
|
Waliso 02 HC
|
35*258/451
|
13
|
7
|
20
|
9
|
Kemate HC
|
25*258/451
|
10
|
5
|
14
|
10
|
Asgori HC
|
22*258/451
|
8
|
4
|
13
|
11
|
Adadi HC
|
20*258/451
|
8
|
4
|
11
|
12
|
Habebe HC
|
18*258/451
|
7
|
3
|
10
|
13
|
Gaba jimata HC
|
8*258/451
|
3
|
2
|
5
|
14
|
Teji HC
|
21*258/451
|
8
|
4
|
12
|
15
|
Dilala HC
|
15*258/451
|
6
|
3
|
9
|
16
|
Odoleka HC
|
10*258/451
|
5
|
2
|
7
|
|
Total
|
|
172
|
86
|
258
|
GH= General Hospital, HC= Health Center
Finally, the selected medical charts were reviewed from May 6 to July 20, 2022
Dependent variables
TB treatment outcome
Independent variable
Nutritional status, the baseline variables were social-demographic factors, Co-morbidity related factors, TB/HIV co-infections, Tuberculosis type, Category of the patients, Year of registration, Drug-related factor, and Treatment center.
Operational definitions
Treatment Outcome-According to the world health organization (WHO guidelines line results were categorized into successful outcomes completed treatment and cured) and unsuccessful outcomes (defaulted, death, and failure)[24].
Cured: Smear-positive pulmonary TB patients who have completed the prescribed course of treatment and have 2 consecutive PTB- results including one after finishing the point of therapy.
Completed treatment: A TB patient who finished treatment without evidence of failure but with no bacteriology result of treatment.
Failure: A TB patient whose sputum smeared positive at 5 months despite correct intake of medication.
Defaulted: Patient who interrupted their treatment for two consecutive months or more after registration.
Death: Patients who died from any cause during the course of treatment.
Nutritional status: it refers to the state of a child’s health in terms of the nutrients in well-nourished and malnourished by Z-scores or standard deviations (<-2 SD) assessed by Anthropometric measurements such as height & weight[25].
Malnourished: Participants with Z-score <-2(<-2-Z-score)
Well nourished: Participants with Z-score>=-2(>=-2-Z-score)(WHO)[24].
Exposure: malnourished and un exposure; well nourished
Data collection Procedure
Data collection tool
Data abstraction was designed based on study objectives and contains three sections that assess the demographic characteristics, nutritional status, clinical characteristics, year of registration, TB types, nutritional support, AFB sputum smear results for study participants, and TB treatment outcomes among children on anti-TB drugs. Data were collected by reviewing medical documents by trained health professionals. The investigators have not been involved in the data collection process. Data collection reviewing TB registration books to identify well-nourished and malnourished by Z-scores[25]. Using TB registration books assess the nutritional status of children undergoing TB treatment. Information on socio-demographics and nutritional support was defined as the receipt of any nutrition-related information or guidance by clinic staff. Participants’ AFB sputum smear results were collected from the review of the TB registration book at two, five, and six months of treatment. Treatment outcomes were assessed based on the WHO classification of treatment outcomes by reviewing TB registration books [24].
Data quality management and validity of measurement
To ensure the quality of the data, a pretest was carried out on 5% of the study samples at another health center and the correction was made based on errors found during the verification process to ensure the agreement of the data abstraction format with the study objectives. The completeness of the collected data was also rechecked by the principal investigator onsite daily during data collection. All completed data collections were examined for completeness and consistency during data management, storage, cleaning, and analysis. Consistency was also assessed by random selection of medical records across-checking them for similarity.
Data processing and analysis
The collected data were cleaned for completeness and consistencies, coded for simplicity, outliers, and missing values were checked and entered into Epi data version 3.1 up on creating the questionnaire template in the QES file of the software and then exported into SPSS for windows version 25 for analysis. Descriptive analysis was undertaken and the result was presented using proportions, percentages, tables, and graphs accordingly. A logistic regression model was used to identify factors associated with the relationship between nutritional status and treatment outcomes among pediatric TB patients and control confounding variables. Firstly, bivariate logistic regression was done for each of the independent factors with TB treatment outcomes; and then those p-values less than 0.25 were again considered as candidate factors for multiple logistic regressions.