RHM 1 Search for studies

• Measured on a scale

–Scale consists of equal intervals of agreed value

• Eg, temperature, height, weight

When working with ___________ data you need to collect:

• Mean value of the outcome measurements
• Standard deviation of the outcome measurements
• Number of participants on whom the outcome was measured

• Dichotomous
• Continuous
• Ordinal
• Counts and rates
• Time to event

What is the total number of participants in the decaffeinated group?

Select the TYPE OF DATA that would be used for the following specific outcome measure:

Select the TYPE OF DATA that would be used for the following specific outcome measure:

Results at 30 minutes following ingestion of coffee (at 10:00 am) indicated that caffeine was useful for reducing fatigue, as measured on a visual analogue scale from 1 (no fatigue) to 100 (extreme fatigue). The mean score (SD) in the caffeine group was 55 (5.5) and 70 (4.8) in decaffeinated group (p=0.04). There was no statistically significant difference in the level of sleepiness between the two groups as measured on the C-Esta Sleepiness Scale by trial personnel (caffeine group: 19 alert/focused, 21 sleepy; decaffeinated group: 17 alert/focused, 23 sleepy).

What is the mean value of fatigue score for the decaffeinated group?

• Time before each participant experiences the outcome of interest
• Eg,

–Time to discharge from hospital

–Time to recurrence of migraine

–Time to death

Select the TYPE OF DATA that would be used for the following specific outcome measure:

Sets of search terms

• Intended to identify a particular study design
• Useful in reducing large numbers of records

• Maps out:

–No. of records identified

–No. of records included and excluded at each stage of the screening process

–Brief summary of the reasons for excluding

What is the number of participants in whom caffeine did not prevent or improve sleepiness?

• There are only two categories
• Eg

–awake or asleep

–in pain or not in pain

–pregnant or not pregnant

When working with _____________ data you need to collect:

• Number of participants with ‘events’ (or in each category).
• Total number of participants in the experimental group.
• Total number of participants in the control groups.

• Lets you see whether the results it identifies are what you expect
• If there are too many, or two few results you can revise your search strategy accordingly

Select the TYPE OF DATA that would be used for the following specific outcome measure:

What is the standard deviation for mean fatigue score in the caffeine group?

What is the standard deviation for mean fatigue score in the caffeine group?

• Categories with a meaningful order
• Not true continuous data

–gaps between the categories may not be equal

• Examples:

–Short: Degree of burns (I-IV), Grades (A to F)

–Long: Quality of life scales, pain scales

• Design strategy before you start research
• Use PICOS format as basis:

–Usually 3 elements are used

–General rule is to use the following 3 elements:

–There are exceptions from the general rule

–Eg, when study is focused on a certain outcome

• NOT controlled by commercial publishers
• Produced on all levels of government, academia, business, and industry
• Produced in print and electronic formats
• Includes:

–Trials, registers, clinical study reports, conference abstracts, dissertations/theses

Select the TYPE OF DATA that would be used for the following specific outcome measure:

• Your included studies may not provide the data you expected, or any usable data at all
• How should you approach these challenges?

What is the upper limit of the scale measuring fatigue?

• Outcomes that may happen to each individual more than once
• Counts

–No. of times an event happened to an individual

• Rates

–Counts measured along with the time

• Eg,

–Number of tick bites per person in a day

–Number of falls per person in a year

Data to collect: Data in any form in which they are given in the study report