and quasi-experimental designs from Schneider, Elloit, Lo Bondo-Wood & Waber.
The study was undertaken by Rebecca Keele-Smith, New Mexico Sate University and Le Cilla Price-Daniel MAJ Army nurse corps at two senior citizen centres, New Mexico City prior to
The purpose of the study was to determine if blood pressure measurement is affected by the leg crossed at the knee as compared with feet flat on the floor. (Keele-Smith, & Price-Daniel, 2001).
The study design was an experimental design. A non-directional hypothesis rather than a research question was used in this study. The hypothesis stated that participants’ blood pressure measurement would be higher with legs crossed rather than uncrossed. The hypothesis was stated in research form and is testable.
Keele-Smith, & Price-Daniel used convinced sampling as a method. The sample was obtained Participants for the study were senior citizens attending activities at two local senior citizen centres’ in New Mexico study. They were recruited by word of mouth and information flyers at local senior centres. Participants could be normotensive or hypertensive. Participants were excluded if they were taking antihypertensives and had not taken there medication the day of the data collection or have had the diagnosis of peripheral vascular disease, had lower leg amputations or surgery within the past 2 weeks. One hundred and ten seniors participated in the study. Seven participants were excluded; 6 participants were excluded because they had not taken their blood pressure medication on the day of measurement and 1 participant had a seizure during data collection.
Keele-Smith, & Price-Daniel stated that power analysis was conducted to determine the appropriate sample size needed to achieve an adequate level of power. The minimum sample size to achieve this was 98, and the study had 103 participants available for data study, thus the results were not due to chance but a real effect.
The researcher did consider the ethical principles of anonymity and confidentiality. The researchers stated that they used a coding system of numbers and they used no participant-identifying information on any data collection instruments. Keele-Smith, & Price-Daniel stated that the participants were informed that the study was voluntary and that they could with draw from the study at anytime. The researchers obtained written informed consent from each participant. Ethical approve to conduct the study was obtained through the Human Subjects Committee at New Mexico state university. The researcher
Random assignment was used to determine which protocols participants received during data collection. The participants, without looking, selected a marble from a basket containing 50 white and 50 turquoise marbles. They were then assigned to either the white-marble protocol or turquoise marble protocol depending on their selection of marbles. After the participants completed a consent form and a demographic form they were taken to a quite room depending on the colour of marble selected. The turquoise marble protocol had participants sitting with feet flat on the floor relaxing for 3 minutes. Blood pressure was measured at the end of the 3-minute period. Participants were then asked to cross one leg over the knee and hold this position for three minutes. Blood pressure measurement was then measured at the end of this three-minute period. The white marble protocol was the reverse of the turquoise-marble protocol. The researcher stated that the purpose of this reverse ordering for part of the sample was to reduce the possibility of ordering effects that could skew the results.
For data analysis the data was grouped into two catergoies:
Descriptive statistics were used
The reported statistics are appropriate for the research question, aims and level of measurement; the sample size is large enough to prevent one score having a large effect on outcome.
The results indicated that blood pressure was significantly higher when legs were crossed versus uncrossed. This was found for both the systolic and diastolic blood pressure. Systolic pressure changed by 5.9mmHg. from 127.32 to 133.24, whereas dialostic pressure changed by 2.97, from 72.54 to 75.52. an comparison of blood pressure measurement between those. There was no significant differences between those who had their blood pressure measured first with their legs crossed versus uncrossed or between those with or without hypertension. These results indicate that blood pressure readings may be artificially high if measured while an individual has a leg crossed.
In the discussion section of the study the researchers did state that even though the study was statistically significant, clinical significance may be limited, as systolic pressure changed only by 5.9mmHg and diastolic changed by only 2.97mm.Hg. However they went onto state that, if a person’s blood pressure measurement is already on the higher end of the normal, even this small amount could effect the clients resulting treatment. The final conclusions drawn from the study by the researchers suggest that instructing patients to keep feet flat on the floor during blood pressure measurement is an important nursing intervention that can contribute to the accurate measurement, interruption and treatment of a patients health condition.
The researchers stated that to improve the strength of the design, random assignment was use to determine which protocol participants received during data collection. Furthermore, training sessions were held for data collectors to ensure consistency of blood measurement technique. All data collectors followed written protocols that had been pilot tested at an earlier time. The researchers stated that they recognised prior to undertaking the study that having legs crossed for inconsistent periods before obtaining measurements could have confounded results, thus a three-minute period was used as described in method.
The only limitation of the study noted by the researchers was the difficulty in keeping the seniors quite during the data collection
The design of the study is appropriate, however, the use of a small aging sample does limit application to general nursing practice. Thus I would not use this article to inform my nursing practice in New Zealand. This study should be repeated using the researchers suggestions; this includes replication of the study using larger samples and among more diverse populations and settings.