Sample Size was determined by using the Lemeshow & Hosmer (1990) sample size formula for case controlled studies:
- Where Zα/2 is the Critical Value of the Normal Distribution=1.96
- Zβ is the Critical Value of the Normal Distribution=1.26
- P1 and p2 are the Expected Sample Proportions of the two Groups.
- p1 = 85% (0.85) Proportion of TB Patients who are Adherent according to previously reported result under Normal TB Treatment Strategy (DOTS),
- And by Hypothesizing p2 = 95% (0.95) and considering 95% Confidence Interval, 80% power, 5% Margin of Error and equal Sample Size for each Group, then the Sample Size will be 137 for each Group.
- To overcome the design effect we assumed Design effect 1.5. The Sample Size was then :137 x 1.5 = 205
- 10% (25) of the Sample will be added to take care of Mortality, Transfers and possible Withdrawals.
- Total Sample size (225) for each Group.
- Total Sample size for the two Groups (450)
- Interventional Group (225) and Control Group (225)
From the targeted sample size of 450 TB patients, 370 were targeted from Nairobi and 80 from Murang’a. Further, 225 patients were allotted to the experimental group and a similar number in the control group. For Nairobi County, 185 patients were allotted for the experimental group and a similar number for the control group and in Murang’a County, 40 patients were allotted in the experimental group and 40 for the control group.
3.7 Patients’ recruitment
TB patients were recruited from the fourteen selected health facilities with the help of the clinical staff in the facilities. In each of these facilities, the TB patient was identified through the TB attendance and treatment registers. To ensure that patients started and ended the health program intervention at the same time, patients who had been on treatment for at least two weeks at the time of selection were recruited. The potential participants were then provided with detailed explanation about the study objectives. After assurance of confidentiality those e willing to participate in the study were asked to sign the Informed Consent Form (additional files).\
3.8 Data collection
The Standard Questionnaire was the main instrument for data collection from the patients. Data was collected on the social-demographic characteristics of the patients. This comprised age, sex, income, education level, employment, residence, household income and household size. Furthermore, data on self-reported adherence to TB treatment was collecting using the Morisky Medication Adherence Scale (MMAS) (Additional files) which measures the drug taking behavior of the patient and reasons for the patient to likely default on medication (18). To capture the TB Patient case management details, a structured Hospital Data Treatment Form was developed. The key parameters for this review included: Name of Health Facility, TB Case, Date Registered, Age, Sex, Residence, TB Supporter, and Contact Details of the Patient. Based on this information, the patients were divided into experimental and control groups.
3.9 Ethical Considerations
Permission was sought from the Kenyatta National Hospital, University of Nairobi Ethics Review Committee, National Commission for Science, Technology and Innovation (NACOSTI), and Nairobi and Murang’a Health Services. The participant’s consent was voluntary, free of any coercion, intimidation or inflated promise of benefits from participation. Care was taken to ensure that the consent form was administered by someone who did not hold authority over the participant. Anonymity, Confidentiality, Secrecy and Privacy were safeguarded with regard to information about Treatment, Medical records and drugs for the TB Patient.
3.10 The Health Education Intervention Program (PRECEDE-PROCEED) Model)
The PRECEDE-PROCEED Model of study (Additional files) was used to implement the health education intervention activities. The various activities and tasks that were carried out were designed to coincide with the time the Patient was seeking TB treatment. Out of 450 respondents the TB patients were divided into two study groups. The experimental group (225) patients who received the health education intervention and the control group which consisted of (225) patients and who did not receive the health education intervention. TB Patients and their Supporters were engaged in a Health Education Program for 10-15 minutes on average. The Health Education Interaction was twice a month for the next 6+ months as the Patient went for the weekly drug ration. For better outcomes, the research encouraged team work among the medical/health staff at facility level in the delivery of the health education program particularly in the mobilization of the patients. However, the main researcher took lead in the entire process. The health education technique used was in form of teaching, questions and answers, interview, discussion and scenario analysis. Education materials consisted of interactive tools including pictures and cards with topics for discussion on basic issues about TB.
The components of the health education provided essential facts about the disease, diagnosis and treatment, potential barriers to treatment adherence, possible adverse effects of the medication, provision of support through counseling and encouragement of social support from family and friends. Pre-test assessment data and post-test assessment data on patient’s demographic characteristics (age, sex, education, marital status, occupation, income etc.) and TB medication and adherence were collected at baseline (first month) and end-term (six months) of the study.
3.11 Statistical methods used
Both descriptive and inferential statistics were used in analyzing data. SPSS v.20 and excel were used to conduct the analysis. Statistical significance was evaluated at p<0.05.
Patient’s social/demographic characteristics (age, sex, education level, marital status, occupation, household size and household incomes) were summarized using descriptive statistics. This was presented in tables showing frequencies, standard deviation and percentages.
MANOVA was used to show the effects of the health education program on TB Patient’s Medication Adherence. The null hypotheses in each of the objectives were tested using Wilk’s Λ followed by ANOVA tests for each of the variables. Levene’s test for equality of variances was used for assumption testing to determine existing variances in the pre and post-test phases.
Chi-square test and Odds Ratio were also calculated for the post-test results to determine the effectiveness of the health education program and ascertain if the patients subjected to health education were faring better than those who were not subjected to the health education program. Chi-square test was also used to test for the associations between socio-demographic factors and adherence to treatment for the post-test phase results.
3.12 Assumptions and Limitation of the Study
The study assumed that all TB cases which were recorded in the counties Public Health facilities and who participated in the study gave the correct information about their social/demographic characteristics, case, treatment and treatment outcomes. It was also assumed that the patients who participated in the study followed the Health Education Intervention Program objectively and honestly shared the effect of the health education experiences. However, there were the possibilities of having obtained less accurate information or biases due to the health state of the patient. Awareness creation and randomization at cluster level ensured bias was minimized.
TB Patients are known to experience stigma. For this reason, discussions about the disease with outsiders may experience some level of rejection. With this knowledge, the researcher worked closely with the TB clinic managers in the health facilities and community health volunteers assigned to the patients.
3.13 Generalization of the Study
This was a Randomized Controlled Trial Design study which ensures bias is minimized hence allowing generalization. The review study was conducted in outpatient TB clinics which were similar to the target setting. The participants of the reviewed studies were also comparable to the target audience. The reviewed studies focused on both male and female adults of varied ethnicity. Public health facilities in Kenya attend to patients of similar characteristics. Furthermore, patients in the review studies were similar to the target population in terms of diagnosis and treatment of the disease. The patients in both the review studies and the present study received standard or Prophylactic Treatment for six months. Therefore, the similarity in setting and target populations in both the review studies and our study meant that findings could be generalized the TB Patients in the proposed settings.