Effect of Breathing Exercise on Certain Physiological Parameters, Sleep Quality and Vitality in Elderly

Study design The study was conducted in a pre-test- post-test, randomised controlled (parallel) and experimental design.

Study population and sample The sample size was determined based on the variable under study (i.e. lung function) using the GPower 3.1.9.4 program. The pretest and post-test "FVC (L)" variable values obtained by Jun et al.18 were taken into account in the effect size calculations, being 3.26 and 3.46, with standard deviations of 0.33 and 0.61, respectively. The calculations identified a sample size that provides α = 0.05, and the power of the test (1-β) = 0.80 indicated a sample size of 26 subjects in each group. Considering the potential for losses over the course of such studies,12,15 20% of the minimum sample size (11 individuals) was added to the study so as not to reduce the statistical power of the study. It was planned in the study to include 32 elderly participants in the intervention group and 31 in the control group.The study was completed with 26 individuals in the intervention group and 25 individuals in the control group.

Sampling After the study protocol was approved by the Institutional Ethics Committee of Gazi University and the Ministry of Family and Social Policies, a nursing home selected previously according to the number of elderly people in residence was selected for the study and approached. Of the 294 elderly residents of the nursing home, 158 were excluded for not satisfying the inclusion criteria, while 60 were unwilling to take part. Consequently, 63 elderly people were entered into the study and were randomly assigned to the intervention or control groups. While assessing the residents in terms of the inclusion criteria in the study, their health status was obtained from the health unit files of the nursing home, and the Mini Mental test was applied by the researcher.

Randomisation Age and gender are significant factors affecting lung and cardiac function, and so a stratified randomization was performed to ensure the similarity of the intervention and control groups. The study participants were stratified by age (65-74 years, and ≥75 years) and gender (female/male) by the researcher, and were then assigned to the intervention and control groups using a simple randomization application within the computer-based SPSS program, with each stratum group divided equally. In this way, a balanced distribution of the groups was achieved without being affected by age and gender. Neither the study participants nor the breathing exercise trainers were blinded in the study, although the respiratory function tests were evaluated by an independent physiotherapist. The participants were called in alphabetical name order, and the measurements were made by an independent physiotherapist. The statistical analyses and reporting were performed by an independent statistician. The data were sent to the statistician with the groups coded as "Group 1" and "Group 2", without distinguishing between the intervention and control groups.

Implementation steps Pre-test: The pre-test measurements were performed by the researcher and a physiotherapy specialist in the physical therapy unit of the nursing home. The participants in both groups were called up for pretest evaluation in alphabetical name order. To begin with, the PSQI and SVS were applied by the researcher, after which the height and body weight of the participant were measured and recorded, along with their age. All these measurements take around 15 minutes. In this way, the elderly were rested and prevented from imbibing anything that could affect lung and heart function, such as cigarettes, tea or coffee, before measurement. The cardiological findings were then evaluated by the researcher. A manual sphygmomanometer and a pulse oximeter were used to assess cardiac function (blood pressure, heart rate, oxygen saturation). Prior to the oxygen saturation measurement, any blue, black, green, brown or red nail polish was removed, along with any artificial nails. Finally, pulmonary function was assessed, for which dentures were removed. The pulmonary function test procedure had been explained and shown previously by the physiotherapist to the elderly participant, and a spirometer was used for the pulmonary function (FVC, FEV1, FEV1/FVC ratio and percentages) measurement. The results were all delivered to the researcher by the authorized representative of the spirometer manufacturer in pdf format within 15 days. All other data were recorded by the researcher after measurement.