Table 3.

Characteristics and quality assessment of included studies

Author	Year of publication	Country study was conducted	Type of study, sample size, gender	Outcome	Exposure characteristics		Effect size/measure (aOR or p value)	Overall quality and capacity to determine if cell spatial density is associated with outcome*
					Cell spatial density values analysed (m2 per person)	Cell design type
Hussain et al 36	2003	Pakistan	Cross-sectional study, 425, 100% male	Mycobacterium tuberculosis	>5.6 vs ≤5.6	Barracks (term not defined and may refer to single and/or multiple person cells	aOR 2.6; 95% CI 1.6 to 4.3	Fair Medium to high risk of: exposure misclassification confounding Potential for: recall bias
Aguilera et al 39	2016	Chile	Cross-sectional study, 418, 77% male	Latent tuberculosis infection	Unclear if continuous or dichotomised variable used.	Not reported	aOR 3.5; 95% CI: 1.1 to 11.5)	Fair Medium to high risk of: exposure misclassification Potential for: recall bias
Hoge et al 35	1994	USA	Cohort study, 46, 92% male	Pneumococcal disease	2.9 vs (4.2 and 2.6);	Single versus (4 persons and dormitory)	aOR 2.0; 95% CI 1.1 to 3.8	Poor to fair Medium to high risk of: exposure misclassification associations due to chance Potential for: recall bias confounding
					13.0 vs (2.9, 4.2 and 2.6);	Single versus (single, 4 persons and dormitory)	P<0.001
					6.8 vs (2.9, 4.2 and 2.6)	Not reported versus (single, 4 persons and dormitory)	P<0.001
Oninla and Onayemi37	2012	Nigeria	Cross-sectional study, 305, 97% male	Infectious dermatoses	0.9 vs 2.4	Single versus dormitories	P=0.03	Poor High risk of: associations due to chance confounding selection bias Potential for: recall bias exposure misclassification
Oninla et al 38	2013	Nigeria	Cross-sectional study, 305, 97% male	Infectious and non-infectious dermatoses	0.9 vs 2.4	Single versus dormitories	P<0.001	Poor High risk of: associations due to chance confounding selection bias Potential for: recall bias exposure misclassification
McCain et al 27	1980	USA	Cross-sectional study, 289, 100% male	Contagious illness reporting at clinic	4.5/5.6 vs 4.6/5.5	Singles/singles versus cubicles/dormitories	P<0.05	Fair Medium to high risk of: outcome misclassification Potential for: associations by chance confounding recall bias selection bias
Gaes40	1982	USA	Cross-sectional study, 352, 100% male	Contagious illness reporting at clinic	4.0 to 8.2	Singles and cubicles	ns	Poor to fair Medium to high risk of: outcome misclassification Potential for: confounding selection bias

*Assessment guided by the NHMRC’s checklist to critically appraise aetiology or risk factor studies.³² Checklist items used to guide the assessment included: exposure misclassification, outcome misclassification, selection bias, confounding and chance.

Bold, statistical significance; ns, not statistically significant.

aOR, adjusted odds ratio.