PUB708 Quantitative Research Methods Essay

Question:

To conduct the study described in your proposal (with appropriate changes if required based on feedback from your proposal), collect the data, describe, analyse, interpret, present and discuss findings.

Answer:

Introduction

It's been a long time since the problem could have a negative impact on the cardiovascular system. Some transversal studies have shown a positive trend in coffee consumption and blood pressure. At least one prospective study involved increased blood pressure. However, inferences should be cautious about causality due to other factors arising from observational studies.

Experimental studies are the best way to determine if there is a relationship and it is an intervention, relevant therapeutic effect of coffee was researched by Lopez-Garcia et al [1]. However, most of these studies were small and could not deliver results to the final, to find the effect of coffee on the subject and whether drinking amount is controversial [2, 3]. The combination of clinical trial in the present work allows for the investigation of the results of gender and age of the participants [4]. In this context, the scholar presented the results of a meta-analysis of 50 clinical studies on the impact of coffee. The present research scrutinized the effect of coffee on participants by investigating two following hypotheses.

  1. H0: Coffee drinking does not have any significant impact on Systolic blood pressure.

HA: Coffee drinking has significant impact on Systolic blood pressure.

  1. H0: Coffee drinking does not have any significant impact on Diastolic blood pressure.

HA: Coffee drinking has significant impact on Diastolic blood pressure.

  • H0: Age of the participants and difference in Diastolic blood pressure do not impact the change in Systolic blood pressure.

HA: Age of the participants and difference in Diastolic blood pressure significantly impact the change in Systolic blood pressure.

  1. H0: Gender of the participants and difference in Diastolic blood pressure do not impact the change in Systolic blood pressure.

HA: Gender of the participants and difference in Diastolic blood pressure significantly impact the change in Systolic blood pressure.

Research Methodology

The scholar advertised the research plan in the University notice board. A pre-formatted form with information fields on biological vitals were circulated to the enrolled applicants through emails. Finally, the participants were selected from total 89 applicants. Applicants with high or low blood pressure were excluded from the study. The scholar also tracked the profile of the applicants and excluded alcohol or substance addicted candidates. At last, 50 participants were selected with average systolic and diastolic blood pressures as 124.4 mm Hg (SD = 12.05) and 79.64 mm Hg (SD = 7.44). Average age of the participants was 25.36 years (SD = 7.03), where females were aged between 19 – 62 years (N = 23, M = 26.78, SD = 9.13), and males were aged between 14 – 38 years (N = 27, M = 24.15, SD = 4.38).

Experiment was introduced after signing of a university approved ethics form. Information about age, gender, primary blood pressure, coffee consumption, coffee volume, and final blood pressure were recorded. Each participant drank a 250 ml hot coffee, and after 3 minutes blood pressure was recorded.

A quantitative analysis of pre and post coffee administration blood pressures by paired t-test was done in SPSS 20 software. The initial blood pressures were considered as control measures, whereas post coffee drinking blood pressures were considered as experimental measures. Correlation between the Systolic and Diastolic pressures was evaluated with linear regression model describing the structure of the relation.

Systolic and Diastolic pressures of the participants for the “Elder” (26 – 62) and “Adult” (14 – 25) blood pressure descriptive have been provided in Table 1.

Initial average Systolic blood pressure for adult and elder participants was found to be almost similar. No noteworthy difference was noted between them regarding the measure.

Initial average Diastolic blood pressure for elder participants (M = 82.37) was found to be greater than that of the adult participants (M = 77.97). The difference in the measure was significant between the two age groups.

Final (after experiment) average Systolic blood pressure for elder participants (M = 128.32) was found to be greater than the adults (M = 122.29). A noteworthy difference was noted between them regarding the measure.

Final (after experiment) average Diastolic blood pressure for elder participants (M = 83.42) was found to be greater than the adults (M = 78.10). A noteworthy difference was noted between them regarding the measure. Effect of Coffee on blood pressure was observed to be greater for the elder participants.

Systolic and Diastolic pressures of the participants were measured, and the gender wise descriptive measures have been listed in Table 2.
Initial average Systolic blood pressure for male participants (M = 125.48) was found to greater than that of the female participants (M = 123.22). The difference noted between the two genders required to be assessed by inferential measure.

Initial average Diastolic blood pressure for female participants (M = 80.22) was found to almost equal to that of the male participants (M = 79.15). No noteworthy difference noted between the two genders regarding the measure.

Final (after experiment) average Systolic blood pressure for male participants (M = 80.22) was found to be greater than the females (M = 80.00). No noteworthy difference was noted between them regarding the measure.

Final (after experiment) average Systolic blood pressure for male participants (M = 124.15) was found to be greater than the females (M = 125.09). No noteworthy difference was noted between them regarding the measure. Coffee drinking was found to rationalize the measure of blood pressures between the two sexes.

Inferential Analysis

The Systolic and Diastolic pressures for control and experimental state were checked for normality by Shapiro-Wilk test. It was discovered that Systolic (W= 0.74, P < 0.05) and Diastolic (W = 0.89, P < 0.05) before coffee drinking were normally distributed. After coffee intake, the Systolic (W= 0.90, P < 0.05) and Diastolic (W = 0.91, P < 0.05) were found to be normally distributed [5].

  1. The claim regarding the impact of coffee on Systolic blood pressure was tested by paired t-test at 5% level of significance. The results indicated that pre and post Systolic pressures were significantly correlated (r = 0.572, p < 0.05) and there was no significant impact of coffee on the Systolic pressure difference (t = -0.096, p = 0.924). Hence, the null hypothesis failed to get rejected at 5% level.
  2. The claim regarding the impact of coffee on Diastolic blood pressure was tested by paired t-test at 5% level of significance. The results indicated that pre and post Systolic pressures were significantly correlated (r = 0.782, p < 0.05) and there was no significant impact of coffee on the Systolic pressure difference (t = -0.684, p = 0.497). Hence, the null hypothesis failed to get rejected at 5% level.
The impact of change in Diastolic pressure, and age of the participants on the modification of Systolic blood pressure was assessed using the ordinary linear regression model. The model was found to be statistically insignificant (F = 0.273, p = 0.762), and the estimating equation was evaluated to be,

Diastolic pressure (t = -0.21, p = 0.84) and age (years) (t = 0.72, p = 0.48) were noted to have no statistically significant effect on the change in systolic blood pressure. The system was found to explain 1.1%% variation of the Systolic pressure after drinking hot coffee. At 5% level of significance, the null hypothesis failed to get rejected.

No multi-co-linearity was observed from the condition index values of the co-linearity diagnostics matrix. The scatter plot of the standardized residuals was found to have homoscedastic nature. Hence, the assumptions of multiple Linear Regression model were not satisfied [6].

The impact of change in Diastolic pressure, and gender of the participants on the modification of Systolic blood pressure was assessed using the ordinary linear regression model. The model was found to be statistically insignificant (F = 0.596, p = 0.555), and the estimating equation was evaluated to be,.

Diastolic pressure (t = -0.031, p = 0.976) and gender (t = - 1.078, p = 0.0287) were noted to have no statistically significant effect on the change in systolic blood pressure. The system was found to explain 2.5%% variation of the Systolic pressure after drinking hot coffee. At 5% level of significance, the null hypothesis failed to get rejected.

No multi-co-linearity was observed from the condition index values of the co-linearity diagnostics matrix. The scatter plot of the standardized residuals was found to have homoscedastic nature. Hence, the assumptions of multiple Linear Regression model were not satisfied (Barker, and Shaw, 2015).

Discussion

The scholar observed that the average systolic blood pressure and that the diastolic blood pressure did not have a significant effect of hot coffee drinking. The effect of coffee consumption was lower for every cup of coffee, and the blood pressure was almost unaffected by the impact. However, the relationship between blood pressure changes and the average age, as well as gender of the participants were found to have no impact whatsoever to define the change in blood pressure levels.

The characteristics of the study participants in the lead time after drinking coffee was not noted, and the scholar missed some vital information [3]. This effect is associated with the quantitative summary of recent experiments. An effect on cardiovascular activity was not discussed in this study [7]. Previous studies have shown that coffee use is accompanied by an increase in systolic and diastolic blood pressure. However, the results of the observation studies were contradictory and difficult to interpret. In summary, the results failed to confirm the relationship between coffee consumption and hypertension. The conduct of high blood pressure tests should be a priority for the future. In addition, it is necessary to further investigate the importance of these factors in smoking and stress, in order to change the effect of consumption of coffee on blood pressure.

References

Lopez-Garcia E, Orozco-Arbel?ez E, Leon-Mu?oz LM, Guallar-Castillon P, Graciani A, Banegas JR, Rodr?guez-Artalejo F. Habitual coffee consumption and 24-h blood pressure control in older adults with hypertension. Clinical Nutrition. 2016 Dec 1;35(6):1457-63.

Kunitake Y, Mizoguchi Y, Sogawa R, Matsushima J, Kato TA, Kawashima T, Monji A. Effect of Excessive Coffee Consumption on the Clinical Course of a Patient With Bipolar Disorder: A Case Report and Literature Review. Clinical neuropharmacology. 2017 Jul 1;40(4):160-2.

Papakonstantinou E, Kechribari I, Sotirakoglou ?, Tarantilis P, Gourdomichali T, Michas G, Kravvariti V, Voumvourakis K, Zampelas A. Acute effects of coffee consumption on self-reported gastrointestinal symptoms, blood pressure and stress indices in healthy individuals. Nutrition journal. 2015 Dec;15(1):26.

Zimmermann-Viehoff F, Thayer J, Koenig J, Herrmann C, Weber CS, Deter HC. Short-term effects of espresso coffee on heart rate variability and blood pressure in habitual and non-habitual coffee consumers–A randomized crossover study. Nutritional neuroscience. 2016 Apr 20;19(4):169-75.

Pandis N. Comparison of 2 means for matched observations (paired t test) and t test assumptions. American journal of orthodontics and dentofacial orthopedics. 2015 Sep 1;148(3):515-6.

Barker LE, Shaw KM. Best (but oft-forgotten) practices: checking assumptions concerning regression residuals. The American journal of clinical nutrition. 2015 Sep 1;102(3):533-9.

Mesas AE, Leon-Mu?oz LM, Rodriguez-Artalejo F, Lopez-Garcia E. The effect of coffee on blood pressure and cardiovascular disease in hypertensive individuals: a systematic review and meta-analysis–. The American journal of clinical nutrition. 2011 Aug 31;94(4):1113-26.

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