Guidelines for Data Processing and
Analysis of the Internationa 丨 Physical
Activity Questionnaire (IPAQ) 一 Short and
Long Forms
November 2005
Contents
Introduction
Us of IPA Q Instruments
Summary Characteristics of Short and Long Forms
Overview of Continuous and Categorical A nalys of IPA Q
Protocol for Short Form
Protocol for Long Form
Data Processing Rules
Summary Algorithms
Appendix 1.
A t A Glance IPA Q Scoring Protocol - Short Forms Appendix 2. A t A Glance IPA Q Scoring Protocol - Long Forms
Introduction This document describes recommended methods of scoring the data derived from the telephone / interview administered and lf-administered IPAQ short and long form instruments. The
methods outlined provide a revision to earlier scoring protocols for the IPAQ short form and
provide for the first time a comparable scoring method for IPAQ long form. Latest versions of
IPAQ instruments are available from www.ipaq.ki.
.
Although there are many different ways to analy physical activity data, to date there is no formal connsus on a …correct‟ method for defining or describing levels of physical activity bad on lf-report population surveys. The u of different scoring protocols makes it very difficult to compare within and between countries, even when the same instrument has been ud. U of the scoring methods will enhance the comparability between surveys, provided identical sampling and survey methods have been ud.
2. Us of IPA Q Instruments
IPAQ short form is an instrument designed primarily for population surveillance of physical activity a
mong adults. It has been developed and tested for u in adults (age range of 15-69 years) and until further development and testing is undertaken the u of IPAQ with older an d younger age groups is not recommended.
IPAQ short and long forms are sometimes being ud as an evaluation tool in intervention studies, but this was not the intended purpo of IPAQ. Urs should carefully note the range of domains and types of activities included in IPAQ before using it in this context. U as an outcome measure in small scale intervention studies is not recommended.
3. Summary Characteristics of IPA Q Short and Long Forms
1. IPAQ asss physical activity undertaken across a comprehensive t of domains
including:
a. leisure time physical activity
b. domestic and gardening (yard) activities
c. work-related physical activity
d. transport-related physical activity;
2. The IPAQ short form asks about three specific types of activity undertaken in the four
domains introduced above. The specific types of activity that are assd are walking, moderate-intensity activities and vigorous-intensity activities.
3. The items in the short IPAQ form were structured to provide parate scores on walking,
moderate-intensity and vigorous-intensity activity. Computation of the total score for the short form requires summation of the duration (in minutes) and frequency (days) of walking, moderate-intensity and vigorous-intensity activities. Domain specific estimates cannot be estimated.
The IPAQ long form asks details about the specific types of activities undertaken
within each of the four domains. Examples include walking for transportation and
moderate-intensity leisure-time activity.
The items in the long IPAQ form were structured to provide parate domain specific
scores for walking, moderate-intensity and vigorous-intensity activity within each of the work, transportation, domestic chores and gardening (yard) and leisure-time domains.
Computation of the total scores for the long form requires summation of the duration (in minutes) and frequency (days) for all the types of activities in all domains. Domain
specific scores or activity specific subscores may be calculated. Domain specific scores require summation of the scores for walking, moderate-intensity and vigorous-intensity activities within the specific domain, whereas activity-specific scores require summation of the scores for the specific type of activity across domains.
4. Overview of Continuous and Categorical A nalys of IPA Q
Both categorical and continuous indicators of physical activity are possible from both IPAQ forms. However, given the non-normal distribution of energy expenditure in many populations, it is suggested that the continuous indicator be prented as median minutes/week or median MET-minutes/week rather than means (such as mean minutes/week or mean
MET-minutes/week).
4.1 Continuous Variables
Data collected with IPAQ can be reported as a continuous measure. One measure of the volume of activity can be computed by weighting each type of activity by its energy requirements defined in METs to yield a score in ME十-minutes. METs are multiples of the resting metabolic rate and a MET-minute is computed by multiplying the Met score of an activity by the minutes performed. MET-minute scores are equivalent to kilocalories for a 60 kilogram person. Kilocalories may be computed from MET-minutes using the following equation: MET-min x (weight in kilograms/60 kilograms). MET-minutes/day or
MET-minutes/week can be prented although the latter is more frequently ud and is thus suggested.
Details for the computation for summary variables from IPAQ short and long forms are detailed below. As there are no established thresholds for prenting MET- minutes, the IPAQ Rearch Committee propo that the data are reported as comparisons of median values and interquartile ranges for different populations.
4.2 Categorical Variable: Rationale for Cut Point Values
There are three levels of physical activity propod to classify populations:
1. Low
2. Moderate
3. High
The algorithms for the short and long forms are defined in more detail in Sections 5.3 and 6.3, respectively. Rules for data cleaning and processing prior to computing the algorithms appear in Section 7.
Regular participation is a key concept included in current public health guidelines for physical activity.1 Therefore, both the total volume and the number of days/ssions are included in the IPAQ analysis algorithms.
The criteria for the levels have been t taking into account that IPAQ asks questions in all domains of daily life, resulting in higher median MET-minutes estimates than would have been estimated from leisure-time participation alone. The criteria for the three levels are shown below.
Given that measures suc h as IPAQ asss total physical activity in all domains, the “leisure time physical activity” bad public health recommendation of 30 minutes on most days will be achieved by most adults in a population. Although widely accepted as a goal, in absolute terms 30 minutes of moderate-intensity activity is low and broadly equivalent to the background or basal levels of activity adult individuals would accumulate in a day. Therefore a 1
Pate RR, Pratt M, Blair SN, Haskell WL , Macera CA, Bouchard C et al. Phy sical activ ity and public health. A recommendation f rom the Centers f or Dia Control and Prev ention and the American College of Sports Medicine. Journal of Am en'can Medical Association 1995; 273(5):402-7. and U.S. Department of Health and Human Serv ices. Physical Activity and Health: A Report of the Surgeon General. Department of Health and Human Serv ices, Centers f or Dia Control and Prev ention, National Center f or Chronic Dia Prev ention and Health Promotion, The Presidents' Council on Phy sical Fitness and Sports: Atlanta, GA:USA. 1996.
new, higher cutpoint is needed to describe the levels of physical activity associated with health benefits for measures such as IPAQ, which report on a broad range of domains of physical activity.
…Hiah，
This category was developed to describe higher levels of participation. Although it is known that greater health benefits are associated with incread levels of activity there is no connsus on the exact amount of activity for maximal benefit. In the abnce of any established criteria, the IPAQ Rearch Committee propos a measure which equates to approximately at least one hour per day or more, of at least moderate-intensity activity above the basal level of physical activity Considering that basal activity may be considered to be equivalent to approximately 5000 steps per day, it is propod that “high active” category be considered as tho who move at least 12,500 steps per day, or the equivalent in moderate and vigorous activities. This reprents at least an hour more moderate-intensity activity over and above the basal level of activity, or half an hour of vigorous-intensity activity over and above basal levels daily. The calculations were bad on emerging results of pedometers studies.2
This category provides a higher threshold of measures of total physical activity and is a uful mechanism to distinguish variation in population groups. Also it could be ud to t population targets for health-enhancing physical activity when multidomain instruments, such as IPAQ are ud.
2 Tudor-Locke C, Bastt DR Jr. How many steps/day are enough? Preliminary pedometer indices f or public health. Sports Med.
2004;34(1):1-8.
…Moderate ，
Revid November2005 5
This category is defined as doing some activity, more than the low active category. It is
propod that it is a level of activity equivalent to “half an hour of at least moderate -intensity
PA on most days”, the former leisure time -bad physical activity population health
recommendation. …Low ，
This category is simply defined as not meeting any of the criteria for either of the previous
categories.
5.
Protocol for IPA Q Short Form 5.1 Continuous Scores
Median values and interquartile ranges can be computed for walking (W), moderate-
intensity activities (M), vigorous-intensity activities (V) and a combined total physical activity
score. All continuous scores are expresd in MET-minutes/week as defined below.
5.2 MET Values and Formula for Computation of MET-minutes/week
The lected MET values were derived from work undertaken during the IPAQ Reliability
Study undertaken in 2000-20013. Using the Ainsworth et al. Compendium (Med Sci Sports
Med 2000) an average MET score was derived for each type of activity. For example; all
types of walking were included and an average MET value for walking was created. The
same procedure was undertaken for moderate-intensity activities and vigorous-intensity
activities. The following values continue to be ud for the analysis of IPAQ data: Walking =
3.3 METs, Moderate PA =
4.0 METs and Vigorous PA = 8.0 METs. Using the values, four
continuous scores are defined:
Walking MET-minutes/week = 3.3 * walking minutes * walking days Moderate
MET-minutes/week = 4.0 * moderate-intensity activity minutes * moderate days Vigorous MET-minutes/week = 8.0 * vigorous-intensity activity minutes * vigorous-intensity days Total physical activity MET-minutes/week = sum of Walking + Moderate + Vigorous MET- minutes/week scores.
5.3 Categorical Score Category 1 Low
This is the lowest level of physical activity. Tho individuals who not meet criteria for
Categories 2 or 3 are considered to have a …low‟ physical activity level.
The pattern of activity to be classified as …moderate‟ is either of the following criteria:
a) 3 or more days of vigorous-intensity activity of at least 20 minutes per day OR
b) 5 or more days of moderate-intensity activity and/or walking of at least 30
minutes per day
OR
c) 5 or more days of any combination of walking, moderate-intensity or vigorous
intensity activities achieving a minimum Total physical activity of at least 600 MET-minutes/week.
3 Craig CL,Marshall A , Sjostrom M et al. International P hysical Activity Questionnaire: 12 country reliability and validity Med Sci
Sports E xerc 2003;August
