Table 3

Effect of multiple NPI combinations on total (camper and staff) COVID-19 cases^*

NPI	Response	Number		Number of cases			RR (95% CI)
NPI	Response	Camps	Campers	Camps	Campers	Staff	Campers	Staff
Camper and staff facial covering	Neither	118	26 589	18	16	39
	Camper facial covering only	0	0	0	0	0	–	–
	Staff facial covering only	137	29 587	41	9	24	0.51 (0.22 to 1.14)	0.55 (0.33 to 0.92)
	Both	126	30 883	13	5	6	0.27 (0.10 to 0.73)	0.13 (0.06 to 0.31)
Camper facial covering and home camper quarantine	Neither	195	42 087	47	11	29
	Camper facial covering only	87	17 547	6	2	2	0.44 (0.10 to 1.97)	0.17 (0.04 to 0.69)
	Home camper quarantine only	56	14 029	12	14	34	3.82 (1.73 to 8.41)	3.52 (2.14 to 5.77)
	Both	34	10 786	4	2	4	0.71 (0.16 to 3.20)	0.54 (0.19 to 1.53)
Camper facial covering and physical distancing	Neither	110	25 477	17	18	32
	Camper facial covering only	21	5019	1	1	0	0.28 (0.04 to 2.11)	0.00 (0.00 to NA)
	Physical distancing only	145	30 699	42	7	31	0.32 (0.13 to 0.77)	0.80 (0.49 to 1.32)
	Both	105	25 864	12	4	6	0.22 (0.07 to 0.65)	0.18 (0.08 to 0.44)
Camper facial coverings and modified programmes	Neither	85	23 113	15	17	31
	Camper facial coverings only	4	662	0	0	0	0.00 (0.00 to NA)	0.00 (0.00 to NA)
	Modified programmes only	167	31 384	44	8	32	0.35 (0.15 to 0.80)	0.76 (0.46 to 1.25)
	Both	120	29 285	13	5	6	0.23 (0.09 to 0.63)	0.15 (0.06 to 0.37)
Physical distancing and modified programmes	Neither	79	19 504	14	17	30
	Physical distancing only	12	4391	1	0	1	0.00 (0.00 to NA)	0.15 (0.02 to 1.09)
	Modified programmes only	54	11 112	4	2	2	0.21 (0.05 to 0.89)	0.12 (0.03 to 0.49)
	Both	238	50 177	55	11	39	0.25 (0.12 to 0.54)	0.51 (0.31 to 0.81)
Physical distancing and home camper quarantine	Neither	99	21 689	10	4	8
	Physical distancing only	186	38 565	44	9	24	1.27 (0.39 to 4.11)	1.69 (0.76 to 3.75)
	Home camper quarantine only	32	8807	8	15	24	9.24 (3.07 to 27.82)	7.39 (3.32 to16.44)
	Both	61	16 008	9	1	16	0.34 (0.04 to 3.03)	2.71 (1.16 to 6.33)
Modified programmes and home camper quarantine	Neither	70	16 915	10	3	9
	Modified programmes only	212	40 724	44	10	23	1.38 (0.38 to 5.03)	1.06 (0.49 to 2.29)
	Home camper quarantine only	19	6860	5	14	22	11.51 (3.31 to 40.03)	6.03 (2.78 to 13.08)
	Both	72	17 955	12	2	18	0.63 (0.10 to 3.76)	1.88 (0.85 to 4.19)

*Comparisons made using subset of data for which there are complete data for each examined NPI. RRs calculated comparing one or two NPIs to neither NPI.
NPI, non-pharmaceutical intervention; RR, relative risk.