Sampling Method and Representativeness Sampling Method The study employed a stratified random sampling technique, wherein the target population was divided into subgroups (strata) based on characteristics such as age, gender, or socioeconomic status. Random samples were then drawn from each stratum to ensure representation across key subgroups. Representativeness Stratified random sampling enhances the representativeness of the sample by ensuring that all relevant subgroups are proportionally included. This approach increases the generalizability of the findings to the broader population. Potential Sources of Selection Bias Despite the strengths of stratified random sampling, potential sources of selection bias include: Non-response bias: Differences between participants who choose to participate and those who do not can affect representativeness. Loss to follow-up: Participants dropping out over time may differ systematically from those who remain, introducing attrition bias. Exclusion criteria: Strict inclusion/exclusion criteria may limit the diversity of the sample and affect generalizability. Quality of Data Collection Methods Validity and Reliability The study utilized standardized and validated instruments for data collection, including structured questionnaires and clinical assessments. Data collectors received comprehensive training to ensure consistency and accuracy. Validity: Instruments measured the intended variables accurately, supported by p