‘Fit to play’: Labour market behaviour in a cohort of public-sector antiretroviral treatment patients

Figures & data

Table 1. Number of patient interviews, by survey round.

Survey round	Baseline	First follow-up	Second follow-up	Third follow-up	Fourth follow-up	Fifth follow-up	Total
A. Original cohort
Interviews conducted	371	307	268	242	219	202	1 609
Patients lost to follow-up		63	38	27	22	19	169
Attrition rate (%)		17.0	10.2	7.3	5.9	5.1	45.6
B. Cohort replacements
Patients recruited		8	29	44	2	0	83
Interviews conducted		8	29	73	64	61	235
Patients lost to follow-up			1	13	14	5	22
Attrition rate (%)			12.5	18.9	11.1	6.0	26.5
C. Follow-up intervals
Median months [interquartile range]		7.0 [5.9 to 8.2]	7.0 [5.8 to 8.2]	6.4 [6.0 to 7.2]	9.1 [7.5 to 10.0]	5.3 [4.4 to 6.3]	6.7 [5.6 to 8.4]

Note: Numbers interviewed and lost to attrition do not add up because of some follow-up interviews, as a result of practical and logistical considerations, being conducted not in the subsequent survey round but in the next round only (e.g. two patients were interviewed at baseline and then again in the third round, but not in round two). Attrition rates are calculated by dividing the number of patients lost to attrition by the number of patients ever interviewed up to and including the previous survey round.

Table 2. Reasons for loss to follow-up.

Reason	Total
	n	%
Deceased	72	43.6
Refusal	28	17.0
Untraceable	21	12.7
Transferred	15	9.1
Migration	15	9.1
Withdrawn/defaulted	7	4.2
Health	3	1.8
Other	4	2.4
Total	165	100.0

Note: Reasons for loss to follow-up are not known for all patients lost to attrition. Percentages may not add up due to rounding.

Table 3. Socio-demographic characteristics of baseline respondents and replacements.

	Original baseline cohort		Replacements		p value
	%	n	%	n
Age
Mean	37.1	371	39.1	77	0.034
Median [interquartile range]	36 [31 to 43]	371	38 [33 to 45]	77	0.068
Female (%)	65.2	371	66.2	83	0.429
Education
None	4.1	15	2.4	2	0.180
Primary	30.9	114	21.7	18
Some secondary	46.6	172	47.0	39
Grade 12	14.6	54	24.1	20
Tertiary	3.8	14	4.8	4
Total	100.0	369	100.0	83
Marital status
Single	49.9	185	45.8	38	0.508
Not cohabiting	29.7	110	36.1	30
Cohabiting	20.5	76	18.1	15
Total	100.0	371	100.0	83
Health status
EQ-5D (0 to 1)	0.773	371	0.802	83	0.459
EQ-VAS (%)	65.2	371	65.8	83	0.816
Feeling ill (%)	30.9	371	21.6	83	0.092
Labour market outcomes
Employed	14.5	54	25.9	21	0.052
Unemployed	15.0	56	18.5	15
Discouraged	14.0	52	14.8	12
Too ill to work	45.8	170	35.8	29
Non-participant	10.5	39	4.9	4
Total	100.0	371	100.0	81

Note: Percentages may not add up due to rounding.

Table 4. Attrition analysis.

	Balanced cohort		Attrition		p value
	%	n	%	n
Age
Mean	38.1	202	36.9	169	0.184
Median [interquartile range]	37 [32 to 44]	202	36 [31 to 43]	169	0.495
Female (%)	68.8	202	60.9	169	0.113
Education
None	4.0	8	4.2	7	0.286
Primary	30.0	60	31.9	54
Some secondary	50.0	100	42.6	72
Grade 12	14.0	28	15.3	26
Tertiary	2.0	4	5.9	10
Total	100.0	200	100.0	169
Marital status
Single	48.5	98	51.4	87	0.643
Not cohabiting	31.6	64	27.2	46
Cohabiting	19.8	40	21.3	36
Total	100.0	202	100.0	169
Health status:
EQ-5D (0 to 1)	0.837	202	0.697	169	<0.001
EQ-VAS (%)	68.0	202	62.0	169	0.004
Feeling ill (%)	25.2	202	37.8	169	0.008
Labour market outcomes
Employed	14.3	29	14.7	25	0.408
Unemployed	16.8	34	13.0	22
Discouraged	15.3	31	12.5	21
Too ill to work	41.5	84	50.8	86
Non-participant	11.8	24	8.8	15
Total	100.0	202	100.0	169

Note: Percentages may not add up due to rounding.

Table 5 Subjective health status and clinical outcomes, by treatment duration.

Outcome	Treatment duration												Sample (n)
	Pre-ART		0 to 3 months		3 to 12 months		12 to 24 months		24 to 36 months		>36 months
CD4 (copies/mm^3)	143	(17.0)	165	(11.0)	254	(10.3)	354	(10.1)	402	(13.3)	449	(20.8)***	1 153
RNA (copies/ml)	249 652	(51 685)	204 747	(33 201)	24 692	(8 121)	3 811	(1 373)	11 909	(4 031)	9 660	(4,918)***	1 137
CD4 > 350 and RNA < 500 (%)	7.6	(4.3)	4.0	(2.0)	17.6	(2.3)	42.1	(2.7)	51.7	(3.3)	60.6	(4.9)***	1 050
Feeling ill (%)	39.3	(4.3)	26.9	(3.2)	26.9	(2.3)	19.7	(1.8)	19.5	(2.1)	15.3	(10.4)***
EQ-5D (0 to 1)	0.706	(0.034)	0.818	(0.020)	0.816	(0.014)	0.833	(0.012)	0.854	(0.013)	0.895	(0.013)***	1 714
EQ-VAS (%)	63.1	(2.0)	66.5	(1.4)	67.7	(1.0)	70.0	(0.9)	71.4	(1.1)	74.9	(1.3)***	1 710
Side effects (%)	50.0	(15.0)	52.6	(4.0)	31.4	(2.5)	10.0	(1.4)	8.1	(1.4)	6.6	(1.7)***	1 541
Severity of side effects (%)
No side effects	50.0		47.7		68.5		89.9		92.8		93.9	***	1 535
Non-disruptive side effects	8.3		4.0		2.3		0.7		0.0		0.0
Minor side effects	16.7		10.6		10.5		2.6		1.6		3.1
Severe side effects	25.0		37.8		18.7		6.8		5.6		3.1
Hospitalised (%)	11.2	(2.8)	8.9	(2.0)	13.2	(1.8)	6.5	(1.1)	6.8	(1.2)	9.0	(2.0)**	1 705

Notes: Standard errors reported in parentheses. Results for side effects only include patients on ARV treatment at the time. Results exclude those patients known to have interrupted their ARV treatment at some time or other during the study (n = 27; N = 130).

***Differences statistically significant at the 1% level. **Differences statistically significant at the 5% level. Medians of continuous variables, however, not reported here due to constraints of space, also differ statistically significantly across treatment duration (p < 0.001).

Table 6. Labour force status, by treatment duration.

	Treatment duration							Total
	HIV-positive diagnosis	Pre-ART	0 to 3 months	3 to 12 months	12 to 24 months	24 to 36 months	>36 months
Employed	18.4	12.3	13.2	16.2	20.9	26.8	26.8	20.4
Unemployed	8.6	14.6	11.6	29.5	25.9	24.1	24.7	23.7
Discouraged	3.2	15.4	15.9	13.3	16.9	13.8	17.0	15.3
Too ill to work	67.6	46.9	46.6	33.7	27.5	25.5	20.1	31.1
None-participants	2.2	10.8	12.7	7.4	8.8	9.8	11.3	9.6
Total	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Sample (n)	315	130	189	353	455	377	194	1 698

Note: HIV diagnosis refers to employment status at first HIV-positive test result. Total excludes figures for ‘HIV-positive diagnosis’. Percentages may not add up due to rounding. Results exclude patients known to have interrupted their ARV treatment at some time or other during the study (n = 27; N = 130). Differences are statistically significant at the 1% level (χ² = 92.37).

Figure 1. Trends in illness/disability among the workforce (%).

Note: Outcomes for ART patients represent results for a balanced panel only (i.e. patients observed in all six survey rounds). Provincial estimates of the numbers of ill/disabled persons in the workforce are not available for all Labour Force Survey (LFS) years. Estimates are for unadjusted LFS data series (Statistics South Africa, 2007–08). LFS estimates are weighted in accordance with the race and sex composition of the CP6 cohort.

Figure 2. Trends in labour force participation rates (%).

Note: Outcomes for ART patients represent results for a balanced panel only (i.e. patients observed in all six survey rounds). Estimates are for adjusted Labour Force Survey (LFS) data series (Statistics South Africa, 2007–08). LFS estimates are weighted in accordance with the race and sex composition of the CP6 cohort.

Figure 3. Trends in unemployment rates (%).

Note: Outcomes for ART patients represent results for a balanced panel only (i.e. patients observed in all six survey rounds). Estimates are for adjusted Labour Force Survey (LFS) data series (Statistics South Africa, 2007–08). LFS estimates are weighted in accordance with the race and sex composition of the CP6 cohort.

Figure 4. Trends in labour force absorption rates (%).

Note: Outcomes for ART patients represent results for a balanced panel only (i.e. patients observed in all six survey rounds). Estimates are for adjusted Labour Force Survey (LFS) data series (Statistics South Africa, 2007–08). LFS estimates are weighted in accordance with the race and sex composition of the CP6 cohort.

Table 7. ARV treatment as predictors of labour market outcomes in public-sector ART clients.

	Too ill to work			Labour force participation			Absorption
	OR	95% CI		OR	95% CI		OR	95% CI
Treated (yes/no)	0.329	[0.133 to 0.813]	p = 0.016	3.257	[1.263 to 8.398]	p = 0.015	1.260	[0.181 to 8.771]	p = 0.814
	F = 2.82 (p < 0.001)	Hausman = 80.15 (p < 0.001)	n = 192 N = 975	F = 1.59 (p = 0.062)	Hausman = 56.40 (p < 0.001)	n = 183 N = 805	F = 2.77 (p < 0.001)	Hausman = 11.32 (p = 0.078)	n = 112 N = 500
Treatment duration (comparison = pre-ART)
0 to 3 months	0.512	[0.181 to 1.444]	p = 0.205	1.019	[0.333 to 3.118]	p = 0.973	1.044	[0.115 to 9.471]	p = 0.969
3 to 12 months	0.236	[0.091 to 0.608]	p = 0.003	4.671	[1.717 to 12.708]	p = 0.003	1.141	[0.130 to 9.986]	p = 0.904
12 to 24 months	0.174	[0.052 to 0.583]	p = 0.005	5.714	[1.571 to 20.774]	p = 0.008	4.098	[0.375 to 44.772]	p = 0.245
24 to 36 months	0.161	[0.033 to 0.778]	p = 0.023	4.830	[0.882 to 26.430]	p = 0.069	5.101	[0.329 to 78.882]	p = 0.241
> 36 months	0.090	[0.013 to 0.595]	p = 0.013	5.853	[0.797 to 42.972]	p = 0.082	3.833	[0.170 to 86.184]	p = 0.394
	F = 2.84 (p < 0.001)	Hausman = 71.72 (p < 0.001)	n = 192 N = 975	F = 2.28 (p = 0.001)	Hausman = 48.39 (p < 0.001)	n = 183 N = 805	F = 2.23 (p = 0.003)	Hausman = 18.33 (p = 0.074)	n = 112 N = 500
Treatment duration (months)	0.960	[0.909 to 1.014]	p = 0.144	1.030	[0.971 to 1.093]	p = 0.314	1.008	[0.903 to 1.126]	p = 0.879
	F = 2.87 (p < 0.001)	Hausman = 72.84 (p < 0.001)	n = 192 N = 975	F = 1.33 (p = 0.169)	Hausman = 68.64 (p < 0.001)	n = 183 N = 805	F = 2.51 (p = 0.001)	Hausman = 41.88 (p < 0.001)	n = 112 N = 500

Note: Results are for multivariate fixed effects logistic regression models. Estimates are adjusted for age, age squared, sex, race, education, dwelling, marital status, household size, dependency ratio, disability grant status, number of employed persons in household (excluding patient), need for secrecy of HIV status, and district – full results are available from the authors on request. p values for coefficients of explanatory variables are derived from robust, Jackknife standard errors. Where regression models failed to converge, the number of iterations in the estimation procedure was set to 100. Test statistics for the overall fit of the regression model and the Hausman specification test are reported for each estimate together with sample sizes (N/n). CI = confidence interval; OR = odds ratio.

Table 8. Health status and clinical outcomes as predictors of labour market outcomes in public-sector ART clients.

	Too ill to work			Labour force participation			Absorption
	OR	95% CI		OR	95% CI		OR	95% CI
Treated * EQ-VAS	0.974	[0.966 to 0.983]	p < 0.001	1.017	[1.008 to 1.026]	p < 0.001	1.017	[1.001 to 1.033]	p = 0.028
	F = 4.32 (p < 0.001)	Hausman = 72.72 (p < 0.001)	n = 192 N = 975	F = 2.00 (p = 0.010)	Hausman = 52.29 (p < 0.001)	n = 183 N = 805	F = 2.41 (p = 0.002)	Hausman = 19.43 (p = 0.021)	n = 112 N = 499
Treated * EQ-5D	0.149	[0.078 to 0.283]	p < 0.001	5.268	[2.574 to 10.783]	p < 0.001	3.332	[0.891 to 12.455]	p = 0.073
	F = 3.87 (p < 0.001)	Hausman = 80.34 (p < 0.001)	n = 192 N = 975	F = 2.19 (p = 0.004)	Hausman = 59.24 (p < 0.001)	n = 183 N = 805	F = 2.50 (p = 0.001)	Hausman = 26.89 (p = 0.002)	n = 112 N = 500
Treated * CD4 > 350 mm^3	1.072	[0.566 to 2.029]	p = 0.829	0.967	[0.540 to 1.734]	p = 0.912	1.155	[0.606 to 2.200]	p = 0.657
	F = 1.62 (p = 0.058)	Hausman = 54.11 (p < 0.001)	n = 133 N = 559	F = 1.89 (p = 0.020)	Hausman = 27.62 (p = 0.003)	n = 121 N = 465	F = 1.81 (p = 0.034)	Hausman = 25.60 (p = 0.012)	n = 84 N = 324
Treated * RNA < 500 ml	0.516	[0.282 to 0.942]	p = 0.032	3.620	[1.695 to 7.732]	p = 0.001	0.770	[0.336 to 1.768]	p = 0.534
	F = 1.69 (p = 0.044)	Hausman = 48.46 (p < 0.001)	n = 137 N = 561	F = 2.21 (p = 0.005)	Hausman = 27.48 (p = 0.003)	n = 124 N = 468	F = 5.80 (p < 0.001)	Hausman = 55.45 (p < 0.001)	n = 80 N = 307
Treated * CD4 > 350 mm^3 and RNA < 500 ml	1.081	[0.562 to 2.079]	p = 0.812	1.138	[0.631 to 2.053]	p = 0.663	1.230	[0.610 to 2.478]	p = 0.557
	F = 1.22 (p = 0.252)	Hausman = 49.80 (p < 0.001)	n = 124 N = 490	F = 1.56 (p = 0.079)	Hausman = 26.42 (p = 0.022)	n = 111 N = 412	F = 4.49 (p < 0.001)	Hausman = 58.26 (p < 0.001)	n = 76 N = 284

Note: Results are for multivariate fixed effects logistic regression models. Estimates are adjusted for age, age squared, sex, race, education, dwelling, marital status, household size, dependency ratio, disability grant status, number of employed persons in household (excluding patient), need for secrecy of HIV status, and district – full results are available from the authors on request. p values for coefficients of explanatory variables are derived from robust, Jackknife standard errors. Where regression models failed to converge, the number of iterations in the estimation procedure was set to 100. Test statistics for the overall fit of the regression model and the Hausman specification test are reported for each estimate together with sample sizes (N/n). CI = confidence interval; OR = odds ratio.

Table 9. Employment status at HIV-positive diagnosis as predictor of labour market outcomes in public-sector ART clients.

	Employed at first HIV+ test (yes/no)
	OR	95% CI
Too ill to work	0.682	[0.409 to 1.138]	p = 0.143
	F = 6.17 ( < 0.001)	LR = 65.85 (<0.001)	n = 305; N = 1 519
Labour force participation	2.396	[1.373 to 4.179]	p = 0.002
	F = 5.67 (<0.001)	LR = 78.47 (<0.001)	n = 302; N = 1 277
Absorption	9.941	[4.600 to 21.484]	p < 0.001
	F = 4.16 (<0.001)	LR = 106.90 (<0.001)	n = 302; N = 1 277

Note: Results are for multivariate random-effects (RE) logistic regression models. Estimates are adjusted for age, age squared, sex, race, education, dwelling, marital status, household size, dependency ratio, disability grant status, health*EQ-VAS, number of employed persons in household (excluding patient), need for secrecy of HIV status, and district – full results are available from the authors on request. p-values for coefficients of explanatory variables are derived from robust, jackknife standard errors (SE). Where regression models failed to converge, the number of iterations in the estimation procedure was set to 100. Test statistics for the overall fit of the regression model and the likelihood ratio (LR) specification test are reported for each estimate together with sample sizes (N/n). CI = confidence interval; OR = odds ratio.

Statistics South Africa, 2007–08. South African Labour Force Survey (LFS). Statistics South Africa, Pretoria.

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