Reference no: EM132368854 , Length: 2500 Words

Dyslipidaemia Study in Diabetes: Study description

A cross-sectional study was conducted on 366 diabetic patients to assess their blood lipid profile and to investigate possible factors contributing to the development of dyslipidaemia among diabetic patients. The patients were recruited from a specialized hospital outpatient department. All study participants provided a blood sample and completed a lifestyle and demographic questionnaire.

The objective of the study was to find factor(s) that may relate to the risk of developing dyslipidaemia in diabetic patients. Along with the demographic information and physical measurements, haematological measurements were reported in continuous scale. For analysis purposes most of the continuous variables were transformed into grouped data. However, original continuous variables were also kept in the data set. The short and long names of the variables and corresponding statistical codes are presented in the following table, Table 1.

Table 1: Variable description of the Dyslipidaemia study

Variable	Variable Label	Value label
ID	ID Number	N/A
Age	Age in years	N/A
Age_gr	Age group	1: < 40 years; 2: 40 - 49 years; 3: 50 - 59 years and 4: >= 60 years
Gender	Gender	1: Male, 2: Female
Occupation	Occupation type	1: Sedentary worker; 2: Moderate worker and 3: Heavy physical worker
Physical_activity	Physical activity level	0 : Sufficient PA and 1 : Insufficient PA
weight	Weight in Kg	N/A
Height	Height in meter	N/A
BMI	BMI in Kg/m2	N/A
BMI_gr	BMI Group	0: Normal; 1: Overweight and 2: Obese
BP_diastolic	Diastolic BP	N/A
BP_systolic	Systolic BP	N/A
HTN	Hypertension	0: Normotensive and 1: Hypertensive
Duration_diabetes	Duration of Diabetes	N/A

Duration_diabetes_ gr	Duration of Diabetes Group	1: < 5 years; 2: 5 - < 10 years and 3: > = 10 years
HbA1c	HbA1c	N/A
HbA1c_gr	HbA1c group	0: <7 Controlled and 1: >=7 Uncontrolled
Insulin	Takes insulin	0: No and 1: Yes
Duration_insulin	Duration of insulin (years)	N/A
T_Chol	Total Cholesterol	N/A
T_Chol_gr	Total Cholesterol group	0: < 200 and 1: ≥ 200
TG	Triglyceride	N/A
TG_gr	Triglyceride group	0: < 150 and 1: ≥ 150
HDL	HDL Cholesterol	N/A
HDL_gr	HDL Cholesterol group	0: Normal and 1: Low
LDL	LDL Cholesterol	N/A
LDL_gr	LDL Cholesterol group	0: < 100 and 1: ≥ 100
Creatinine	Serum Creatinine	N/A
Creatinine_gr	Serum Creatinine	0: < 1.5 and 1: ≥ 1.5
TC_HDL	TC_HDL ratio	N/A
LDL_HDL	LDL_HDL ratio	N/A
Dyslipidaemia	Dyslipidaemia	0: No dyslipidaemia and 1: Yes dyslipidaemia

Questions 1-3 are related to the "Dyslipidaemia Data".

Question 1:  Identify each of the variables in the above table either as nominal, ordinal, discrete or continuous.
Hint: Present your answer in a table by listing the variables in the first column, classification of the variables in the second and value label in the third column.

Question 2: Fill up the following table using appropriate summary statistics for each of the listed variables. Discuss whether dyslipidaemia is related to HbA1c, diastolic BP, insulin status and patients' age.
Hint: outcome variable is dyslipidaemia.

Hints:
• Evaluate the conditions (if any) that you should check before reporting summary statistics for each of the numerical variables in this question.
• Discuss the results and make a brief summary conclusion in the context of the study. Please present the discussion and conclusion separately.
• Present the relevant analysis output in an appendix along with the table/graph number and appropriate title for the table/graph (copy and paste all analysis output in a picture format by using "Copy Special" - please see next bullet point).
• How to copy and paste? Here is the solution: In the SPSS output, if you right click on the graph or table, as if you were going to copy it, there is an option for "Copy Special". Click this and then uncheck all options and check the Image (JPG, PNG) option. This will save the graph or table as an image. When you paste it into a word document you can drag the corners to resize the image to your liking.

Question 3: Graphically determine the relationship between dyslipidaemia and each of the following variables: duration of diabetes group, BMI group and occupation type. Present each of the above variables on an appropriate graph and discuss.

Hints:
(a) Justify the choice of the graphs that have been used.
(b) Discuss the results and make a brief summary conclusion in the context of the study.
(c) Present the graphs in the text along with the graph number and appropriate title for the graph (copy and paste all graphs in a picture format, see the instructions provided in Question 2 above)

Cardiovascular Disease Study (CVD-Data)

Consider a study where twelve baseline variables (e.g., age, gender, weight, BMI, etc.) among others were collected from each of the 1429 participants. Out of the 1429 participants, 952 had a history of being treated with Drug-X on a regular basis. The objective of the study was to investigate whether Drug- X was protective for various risk factors of cerebrovascular vascular disease (CVD). The participants were then followed for 5 years and their mortality status was recorded. The short and long names of the variables are given in Table 2.

Table 2: Variable description for the study

 

Variable	Description	Statistical Code (if any)
AGE	Age	N/A
GENDER	Gender	0 for female and 1 for male
WEIGHT	Weight	N/A
BMI	Body mass index	0 for <25; 1 for 25 to <30; 2 for 30 to <35 and 3 for 35 and above
SBP	Systolic blood pressure	N/A
DBP	Diastolic blood pressure	N/A
CHL	Cholesterol level	N/A
SMOKE	Smoking status	0 for never smoked and 1 for smoked
Drug-X	Drug "X" treated	0 for no and 1 for yes
PAD	Peripheral arterial disease	0 for no and 1 for yes
STROKE	Stroke	0 for no and 1 for yes
DEATH	Follow-up mortality status	0 for no and 1 for yes

Questions 4-7 are related to the CVD-Data.sav

Hints for Questions 4 & 5:
(d) Justify the choice of the graphs that have been used,
(e) Present the graphs in the text along with the graph number and appropriate title for the graph (please use the special copy and paste option when copying and pasting from SPSS),
(f) Discuss the results and make a brief conclusion in the context of the study.

Question 4: Consider that an investigator aims to assess whether followed-up mortality (DEATH) was related to body mass index (BMI, a categorical variable) in the study sample. Evaluate the investigator's aim by presenting the related data on an appropriate graph.

Hint: no additional summary statistics or significance test required.

Question 5: Using an appropriate graphical presentation discuss whether diastolic blood pressure (DBP) is related to body mass index (BMI, a categorical variable) in the study sample
Hint: no additional summary statistics or significance test is required.
Based on the findings can you make an inference on the study population? Justify your answer.

Hints for Questions 6 & 7:
Justify the choice of the statistical methods that have been used,
Present the data analysis output graphs/tables in an appendix along with the graph/table number and appropriate title for the graph/table (please use the special copy and paste option when copying and pasting from SPSS),
For statistical significance tests, please follow the steps that have been outlined in the lecture and tutorial slides. All steps should be in the context of the study.
Interpretation for some of the results are required.

Question 6: Using appropriate statistical method(s) investigate whether patients who had a history of being treated with Drug-X on a regular basis have significantly different systolic blood pressure (SBP), diastolic blood pressure (DBP) and cholesterol level (CHL) compared to patients who were not treated with Drug-X.

Please fill up the following table from the above analysis results

Hint: Please do not discuss the steps of significance tests for each of the variables separately. Instead combine SBP, DBP and CHL in each step.

Note: Five marks will be allocated for successful combination of the results.

Question 7: Using an appropriate statistical method evaluate the significance of difference of SBP across the following categories of BMI: BMI <25, BMI 25 to <30 and BMI ≥ 30kg/m².

Attachment:- Biostatistics Assessment.rar