Table of Contents

SQUASH (sum scores)

Researchers from the University Medical Center Groningen used the raw data from the SQUASH instrument in 1A Questionnaire 2 to calculate the sum scores for physical activity per activity type and overall for all adult participants who sufficiently filled in the questionnaire (sections: lifestyle & environment and secondary & linked variables).

The SQUASH sum scores can be requested in the Lifelines catalogue. Only the final results are present in the Lifelines catalogue, if you would like to receive the extensive version (including all intermediate variables) we assume you understand the data. The extensive version can be requested by mailing data@lifelines.nl. When the SQUASH sum scores have been used in your research, you can refer to the Chapter 7 of the following thesis:


Data processing (part 1)

The calculation of the SQUASH sum scores according to Wendel-Vos et al. (2004) consisted of three consecutive steps: (1) calculation, (2) conversion, and (3) categorization. Below the steps are briefly described; for a more detailed description we refer to Byambasukh, O. (2020). The results of this syntax have been released as SQUASH sum scores previously (version 1).


Data processing (part 2 + 3)

After the first SQUASH sum scores were finalized, the following observations made the UMCG researchers who developed the SQUASH sum scores reconsider their results:

  1. Total physical activity in minutes/week should not be used as a measure of physical activity because this measure includes light physical activity, and light physical activity entails a high risk of obtaining imprecise estimates of total minutes of light PA and because of potential bias relating to occupational status.
  2. Moderate to vigorous physical activity (MVPA) measured in minutes/week is the best variable to rank individuals by level of physical activity.
  3. Updated MET values (derived from the 2011 version of compendium) should be applied to calculate the MVPA, but without age correction during data processing. In other words, in the absence of a sound and validated rationale for the inclusion of age correction in data processing, the same categories of intensity should be applied for adults belonging to both younger (18–55 years) and older (>55 years) age groups.
  4. An alternative outcome for physical activity that is often used is ‘MET-minutes’. However, if updated MET values derived from the 2011 version of the Ainsworth’s compendium are used, MET values for cycling conducted as a commuting or leisure-time activity should be set at 5.0 to avoid overestimating vigorous PA. Moreover, it is best to use ‘MET-minutes in MVPA’, thus MET-minutes for the moderate to vigorous levels (selecting MET ≥ 4) because of the high risk of obtaining imprecise estimates for light PA minutes.
  5. Compared with occupational PA, leisure time and commuting PA demonstrate a much clearer association with health outcomes. Therefore, we recommend to make a substantiated decision to include or exclude occupational PA in the PA measure you want to use, since PA in the various domains seem to represent different kinds of activity with differential health effects.


In the end, it was decided to make the following adjustments to the syntax of Wendel-Vos et al. (2004):

Additionally, it was decided to release the composed variables only. And have the variables necessary to get to the result available on request only. As these variables require some understanding of the SQUASH (e.g. consideration of plausibility/correctness of the light physical activity category).


Variables

Label English Label Dutch Code Variable Assessment Age
moderate intensity, activity score (version 2) matig intensief, activiteitenscore (versie 2) m_scor_v2 squashsum_activityscore_adu_c_2_b 1A2 18+
vigorous intensity, activity score (version 2) zwaar intensief, activiteitenscore (versie 2) z_scor_v2 squashsum_activityscore_adu_c_2_c 1A2 18+
moderate intensity, minutes per week (version 2) matig intensief, minuten per week (versie 2) m_mwk_v2 squashsum_minperweek_adu_c_2_b 1A2 18+
vigorous intensity, minutes per week (version 2) zwaar intensief, minuten per week (versie 2) z_mwk_v2 squashsum_minperweek_adu_c_2_c 1A2 18+
complete questionnaire missing hele vragenlijst niet ingevuld totmis squashsum_missing_adu_c_1 1A2 18+
commuting: missing (version 2) woonwerk: niet ingevuld (versie 2) wwmis_v2 squashsum_missing_adu_c_2_a 1A2 18+
household activities: missing (version 2) huishouden: niet ingevuld (versie 2) hhmis_v2 squashsum_missing_adu_c_2_b 1A2 18+
leisure time: missing (version 2) vrije tijd: niet ingevuld (versie 2) vtmis_v2 squashsum_missing_adu_c_2_c 1A2 18+
work: missing (version 2) werk: niet ingevuld (versie 2) werkmis_v2 squashsum_missing_adu_c_2_d 1A2 18+
moderate-to-vigorous physical activity, total minutes per week (new version 2) matig tot zwaar inspannend fysieke activiteit, totaal minuten per week (nieuw versie 2) mvpa_mwk squashsum_mvpaduration_adu_c_1 1A2 18+
moderate-to-vigorous physical activity,activity score (new version 2) matig tot zwaar inspannend fysieke activiteit, activiteitenscore (nieuw versie 2) mvpa_scor squashsum_mvpascore_adu_c_1 1A2 18+
identifier of complete and reliable squash questionnaire identificatie van een volledige en betrouwbare squash vragenlijst squash_com_rel squashsum_reliability_adu_c_2 1A2 18+