Validity of subjective smoking status in orthopedic patients

Figures & data

Figure 1 Serum cotinine levels.

Notes: White boxes: levels at preoperation; gray boxes: levels at follow-up. Black lines indicate medium; bottom and top of the boxes indicate the first and third quartile, respectively. Whiskers indicate the lowest and highest values within 1.5 interquartile range. Outliners above and beyond extremes are not shown.

Table 1 Patients’ characteristics

	Sex		Age (years)	BMI (kg/m^2)	Location					Serum cotinine		Total
	M	F	Median (min, max)		Humerus	Forearm	Femur	Lower leg	Other	Negative	Positive
Subjective
NS	28	37	53 (20, 89)	28 (18, 42)	9	1	23	31	1	61 (92.8%)	4 (6.2%)	65 (48%)
PS	17	9	51 (22, 84)	28 (21, 52)	3	2	8	12	1	20 (76.9%)	6 (23.1%)	26 (19%)
CS	29	16	50 (23, 78)	27 (19, 35)	2	3	16	23	1	6 (13.3%)	39 (79.6%)	45 (33%)
Total	74	62	51 (20, 89)	28 (18, 52)	14	6	47	66	3	87 (64%)	49 (36%)	136 (100%)

Notes: Negative, serum level below cut-point; positive, serum level above cut-point.

Abbreviations: M, male; F, female; BMI, body mass index; NS, nonsmoker; PS, previous smoker; CS, currect smoker.

Table 2 Prevalence of smoking as measured by subjective status and serum cotinine testing

	Subjective status			Serum testing		Total
	NS	PS	CS	Negative	Positive
Male	28	17	29	42	32	74
Of all male patients (%)	37.8	23.0	39.2	56.8	43.2	100
Female	37	9	16	45	17	62
Of all female patients (%)	59.7	14.5	25.8	72.6	27.4	100
Total	65	26	45	87	49	136
Of all patients (%)	47.8	19.1	33.1	64.0	36.0	100

Notes: Percentages indicate prevalence within sexes and within general population; negative, serum level below cut-point; positive, serum level above cut-point.

Abbreviations: NS, nonsmoker; PS, previous smoker; CS, currect smoker.

Table 3 Test quality of subjective smoking status

Subjective status	Serum testing
	Positive	Negative
Current smokers	39	6
Patients above cut-point (%)	79.6	6.9
Nonsmokers and previous smokers	10	81
Patients above cut-point (%)	20.4	93.1
Total	49	87

Notes: Negative, serum level below cut-point; positive, serum level above cut-point.