Table 1.

Characteristics of included studies

ReferenceStudy design, NStudy regionMean age (SD)Physical activity domainAssessment of physical activityTiming in life of physical activityDefinition of highest/lowest activity levelAdjustment
Brownson and colleagues, 1991 (28)Case–control in men 536 non-Hodgkin lymphoma 16,611 controls (other cancer type).US (Missouri)20 years or older at time of diagnosis (mean age not reported)OccupationalRecorded by hospital registrars using a standardized protocol. The classification scheme of Garabrant and colleagues (50) with modifications from Missouri work requirements (49) was used to categorize occupations according to the level of physical activityAt the time of diagnosisPhysical activity required > 80% of the time versus < 20% of the timeAge, smoking
Zahm and colleagues, 1999 (30)Case—control 1,177 non-Hodgkin lymphoma (993 M) 3,625 controls (2,918 M)US (Iowa, Kansas, Minnesota and Nebraska)20–75+OccupationalInterview. Occupational job titles were coded with the 1977 Standard Occupational Classification system (51) and the 1977 Dictionary of Occupational Titles (52)Usual occupationEnergy expenditure > 12 kJ/min versus < 8 kJ/min for men and > 8 kJ/min versus < 5 kJ/min for womenAge, state of residence
Cerhan and colleagues, 2005 (31)Case—control 1,321 non-Hodgkin lymphoma (571 M) 1,057 controls (550 M)US (Detroit, Iowa, Los Angeles and Seattle)58.1 (range 20–74)RecreationalFour self-administered questions, including one on household activity, one on moderate physical activity and one on vigorous physical activityBefore one year> 1,080 Mets/wk versus < 30 Mets/wkAge, gender, race, study center
OccupationalFour self-administered questions, including one question on occupational physical activityBefore one yearTime at work characterized by mostly manual labor or exercise versus mostly sit
Pan and colleagues, 2005 (32)Case–control 1,030 non-Hodgkin lymphoma (569 M) 3,106 controls (1,642 M)CanadaCases: 58.9 (8.01) Controls: 59.6 (7.91)RecreationalSelf-administered questionnaire about recreational physical activity 2 years before interview, investigator-designed2 years before interview≥37.4 Met-h/wk versus <6.4 Met-h/wkAge, province, education, pak-years of smoking, acohol drinking, exposure to some chemicals, occupational exposure, BMI, total calorie intake
Keegan and colleagues, 2006 (33)Case-control in women 312 Hodgkin lymphoma 325 controlsUS (Greater Bay Area of northern California)15–79RecreationalInterview about participating in strenuous physical activity or sports. Questions were taken from an instrument used by the Collega Alumni Health Study (53)The past yearStrenuous physical activity at least twice a week for ≥1 months: yes versus noAge, race/ethnicity, education, Jewish bringing-up, single room at age 11, living in a single family home at age 8, number of miscarriages, smoking status 1 year before interview, history of first or second degree relative with lymphoma, having ever nursed children
Lim and colleagues, 2007 (29)Cohort 285,079 M 188,905 F 58 Hodgkin lymphoma, 1,381 non-Hodgkin lymphomaUS (California, Florida, Louisiana, New Jersey, North Carolina, Pennsylvania, Atlanta, Detroit)50–71TotalSelf-administered questionnaire: frequency of activities that lasted at least 20 minutes and caused breathing or heart rate increase or sweatingAt time of enrolment3–4 times/wk versus < 1/wkAge, gender, race, education, BMI and caloric intake
Lu and colleagues, 2009 (39)Cohort 121,216 F 574 B-cel non-Hodgkin lymphoma casesUS (California)range: 19–79RecreationalSelf-administered questionnaire about strenuous and moderate recreational physical activity, investigator-designedThe past 3 years≥4 h/wk/year versus 0–0.5 h/wk/yearHeight, weight, age at menarche
Van Veldhoven and colleagues, 2010 (36)Cohort 127,353 M 216,403 F 778 non-Hodgkin lymphoma casesEurope (Denmark, France, Germany, Greece, Italy, the Netherlands, Norway, Spain, Sweden, and the United Kingdom)M: 52.9 (9.8) F: 51 (10.9)TotalA total physical activity index created by Friedenreich and colleagues, based on four self-administered or interview-based question about occupational, household and recreational physical activity during the past year, derived from development work undertaken in the Netherlands. Validated and repeatable index (54).At the time of enrolmentVery high recreational physical activity (≥45.75 Met-h.wk−1) in combination with (heavy) manual work or standing occupation versus low or medium recreational physical activity (<27.75 Met-hr.wk−1) in combination with sedentary or unknown occupationAge, hypertension, hyperlipidaemia, education, diabetes
RecreationalFour self-administered or interview-based question about occupational, household and recreational physical activity during the past year, derived from development work undertaken in the Netherlands.≥45.75 Met-h/wk versus < 14.25 Met-hr/wk
OccupationalFour self-administered or interview-based question about occupational, household and recreational physical activity during the past year, derived from development work undertaken in the Netherlands.(Heavy) manual versus sedentary occupation
Kabat and colleagues, 2011 (37)Cohort 158,975 F 1,123 non-Hodgkin lymphoma casesUnited States63.2 (7.2)RecreationalSelf-administered questionnaire about the usual pattern of activityAt the time of enrollment≥17.5 Met-h/wk versus <1.6 Met-hr/wkAge, pack-years of smoking, servings of alcohol per week, education, BMI, ethnicity
Parent and colleagues, 2011 (34)Case-control in men 215 non-Hodgkin lymphoma, 54 Hodgkin lymphoma 533 controlsCanada (Montreal)Cases: 58.9 (8.01) Controls: 59.6 (7.91)TotalInterview about occupational and recreational physical activityDuring adult lifeIntermediate level of occupational physical activity [<75% of work years spent in very active (≥4 Mets) or sedentary jobs (≤1.5 Mets)] with recreational activities, or at the high occupational physical activity level (≥75% of work years spent in very active jobs, ≥4 Mets) with or without recreational physical activity versus low occupational physical activity level (>75% of work years spent in sedentary jobs (≤1.5 Mets) or intermediate occupational physical activity level without recreational physical activityAge, socio-economic status, educational level, ethnicity, respondent status, smoking BMI
RecreationalInterview about recreational physical activityDuring adult lifeSports and/or outdoor activities on average once a week or more for at least 6 months: yes versus no
OccupationalInterview about occupational physical activityDuring adult lifeAt least 75% of work years spent in very active jobs (4 MetS or more) versus at least 75% of work years spent in sedentary jobs (≤1.5 Mets)
Teras and colleagues, 2012 (38)Cohort 69,849 M 77,001 F 2,002 non-Hodgkin lymphoma cases21 states of America62.9 (6.4)RecreationalSelf-administered question about the frequency of several leisure-time activitiesThe past year≥17.5 Met-h/wk versus 0–7 Met-hr/wkAge, family history of hematopoietic cancer, education, smoking status, alcohol intake, BMI, height
Kelly and colleagues, 2012 (35)Case–control 950 non-Hodgkin lymphoma (550 M) 1,146 (611 M)US (Minnesota)Median: 63TotalSelf-administered questions on duration and frequency of walking, mild, moderate, and strenuous physical activity 2 years before case diagnosis or control selection2 years before case diagnosis or control selection>2,701 Mets/wk versus < 615 Mets/wkAge, gender, county of residence

Abbreviations: BMI, body mass index; F, female; kJ, kilojoule; M; male; MET, metabolic equivalent (3.5 mlO2/kg/min).