Figures and data in Productivity loss associated with functional disability in a contemporary small-scale subsistence population

Figures
Tables
Additional files

6 figures, 16 tables and 1 additional file

Figures

Figure 1

Download asset Open asset

Tsimane women weaving bags used for carrying diverse objects (left panel; photo credit: Jonathan Stieglitz) and ground mats used for resting (right panel; photo credit: Arnulfo Cary).

Finished woven products are also shown in each panel.

Figure 2

Download asset Open asset

Top: Proportion of Tsimane men with thoracic vertebral body fracture (grade ≥1) by age, estimated using the loess function.

The shaded region shows ±1 SE, and jittered data points represent fracture status. Bottom: scatterplot of thoracic vertebral body bone mineral density (BMD) by age and fracture status, including linear regression lines for each fracture status. N = 256 men.

Figure 3

Download asset Open asset

Top: Proportion of Tsimane women with thoracic vertebral body fracture (grade ≥1) by age, estimated using the loess function.

The shaded region shows ±1 SE, and jittered data points represent fracture status. Bottom: scatterplot of thoracic vertebral body bone mineral density (BMD) by age and fracture status, including linear regression lines for each fracture status. N = 237 women.

Figure 4

Download asset Open asset

Top: Age-specific productivity (kcals/day) for hunting by men’s fracture status, and for fishing (all men).

Bottom: expected cumulative future productivity (millions of kcals) from age x onward, discounted by mortality, for hunting by men’s fracture status, and for fishing (all men).

Figure 5

Download asset Open asset

Top: Age-specific productivity (kcals/day) for hunting by men’s fracture status and bone mineral density (BMD), and for fishing (all men).

For illustrative purposes we show daily hunting production for men with +1 SD and −1 SD of the BMD mean. Bottom: expected cumulative future productivity (millions of kcals) from age x onward, discounted by mortality, for hunting by men’s fracture status and BMD, and for fishing (all men).

Figure 6

Download asset Open asset

A conceptual model linking somatic condition to economic productivity during aging in small-scale subsistence societies.

Variables in red are a focus of the present study.

Tables

Table 1

Percentage of men (95% CI) who completely ceased hunting by age and thoracic vertebral body fracture status.

Age category (years)	% ceased hunting with fracture	N	% ceased hunting without fracture	N
40–49	8^{^} (<1–19)	26	0 (-----)	55
50–59	33^*** (17–50)	36	4 (<1–9)	56
60–69	50^{^} (24–76)	18	27 (12–42)	37
70+	100^* (-----)	12^†	63 (36–89)	16^‡
Total	38^*** (28–48)	92	13 (8–19)	164

^{^}p≤0.1, ^*p≤0.05, ^**p≤0.01, ^***p≤0.001 (χ² or Fisher’s Exact Test [vs. no fracture]).

^†Max age = 83 years (mean ± SD = 75 ± 4).
^‡Max age = 81 years (mean ± SD = 74 ± 3).

Table 2

Percentage of men (95% CI) who completely ceased tree chopping by age and thoracic vertebral body fracture status.

Age category (years)	% ceased tree chopping with fracture	N	% ceased tree chopping without fracture	N
40–49	15^** (1–30)	26	0 (-----)	55
50–59	39^*** (22–56)	36	4 (<1–9)	56
60–69	67 (43–91)	18	54 (37–71)	37
70+	100 (-----)	12^†	81 (60–100)	16^‡
Total	46^*** (35–56)	92	21 (15–28)	164

^{^}p≤0.1, ^*p≤0.05, ^**p≤0.01, ^***p≤0.001 (χ² or Fisher’s Exact Test [vs. no fracture]).

^†Max age = 83 years (mean ± SD = 75 ± 4).
^‡Max age = 81 years (mean ± SD = 74 ± 3).

Table 3

Percentage of women (95% CI) who completely ceased weaving by age and thoracic vertebral body fracture status.

Age category (years)	% ceased weaving with fracture	N	% ceased weaving without fracture	N
40–49	0 (-----)	11	0 (-----)	72
50–59	14 (<1–29)	22	5 (<1–11)	60
60–69	33 (<1–72)	9	24 (10–39)	37
70+	75 (<1–100)	4^†	55 (32–77)	22^‡
Total	20 (8–31)	46	13 (8–17)	191

^{^}p≤0.1, ^*p≤0.05, ^**p≤0.01, ^***p≤0.001 (χ² or Fisher’s Exact Test [vs. no fracture]).

^†Max age = 91 years (mean ± SD = 80 ± 9).
^‡Max age = 91 years (mean ± SD = 77 ± 6).

Table 4

Percentage of adults (95% CI) who are unable to walk a full day by age and thoracic vertebral body fracture status.

Age category (years)	% unable to walk all day with fracture	N	% unable to walk all day without fracture	N
40–49	49^*** (32–66)	37	19 (12–26)	127
50–59	64^*** (51–77)	58	27 (19–35)	116
60–69	89^** (76–100)	27	64 (52–75)	74
70+	100^{^} (-----)	16^†	84 (72–96)	38^‡
Total	69^*** (61–77)	138	38 (33–43)	355

^{^}p≤0.1, ^*p≤0.05, ^**p≤0.01, ^***p≤0.001 (χ² or Fisher’s Exact Test [vs. no fracture]).

^†Max age = 91 years (mean ± SD = 76 ± 6).
^‡Max age = 91 years (mean ± SD = 76 ± 5).

Appendix 1—table 1

Descriptives for study variables*.

Variable	N	Mean	SD	Min	Max
Thoracic vertebral body BMD (mg/cm³)	493	165.5	41.3	68.9	315.0
Any thoracic vertebral body (T6–T12) fracture (proportion grade ≥1)	493	0.28	0.45	0	1
Any thoracic vertebral body (T6–T12) fracture (proportion grade ≥2)	493	0.09	0.29	0	1
Age (years)	493	55.9	9.9	41.2	91.0
Sex (proportion male)	493	0.52	0.5	0	1
Height (cm)	489	156.1	7.6	136.0	176.3
Weight (kg)	489	58.7	9.8	34.6	96.9
Body fat (%)	445	21.5	8.0	5.0	46.7
Fat mass (kg)	445	12.9	6.1	1.9	42.1
Fat-free mass (kg)	445	45.8	7.9	27.8	73.1

^*Data were missing for various reasons (see Appendix for details).

Appendix 1—table 2

Percentage of men (95% CI) who completely ceased hunting by age and thoracic vertebral body fracture status (fracture grade ≥2).

Age category (years)	% ceased hunting with fracture	N	% ceased hunting without fracture	N
40–49	0 (-----)	4	3 (<1–6)	77
50–59	21 (<1–46)	14	14 (6–22)	78
60–69	60 (<1–1)	5	32 (19–45)	50
70+	100 (-----)	6^†	73 (53–93)	22^‡
Total	41^** (22–60)	29	20 (15–25)	227

^{^}p≤0.1, ^*p≤0.05, ^**p≤0.01, ^***p≤0.001 (χ² or Fisher’s Exact Test [vs. no fracture]).

^†Max age = 83 years (mean ± SD = 74 ± 4).
^‡Max age = 83 years (mean ± SD = 74 ± 3).

Appendix 1—table 3

Binary logistic regression: effect of thoracic vertebral body fracture on the probability of hunting cessation after adjusting for age (model 1; n = 256 men).

Model 2 additionally includes as a covariate thoracic vertebral body bone mineral density (BMD). Shown are odds ratios (95% CIs); continuous variables are z-scored.

Parameter	Model 1	Model 2 (+BMD)
Any thoracic vertebral body fracture (grade ≥1; vs. none)	7.3^***(3.3–17.6)	7.4^***(3.3–18.2)
Age (years)	5.2^***(3.4–8.5)	4.1^***(2.5–7.0)
Thoracic vertebral body BMD (mg/cm³)	-----	0.62^*(0.38–0.99)

AIC	178.55	176.61

^{^}p≤0.1, ^*p≤0.05, ^**p≤0.01, ^***p≤0.001 (refer to main text for FDR q-values)

Appendix 1—table 4

Tsimane men’s age-specific daily hunting production by thoracic vertebral body fracture status.

Age (years)	(A) Hunt cals/day^†	(B) Probability still hunting: no fracture^‡	(C) Probability still hunting: fracture^‡	(D) Hunt cals/day: no fracture^§	(E) Hunt cals/day: fracture^¶
40	1872	0.995	0.968	1864	1812
41	1884	0.995	0.962	1874	1813
42	1888	0.994	0.955	1875	1803
43	1882	0.992	0.947	1868	1783
44	1870	0.991	0.938	1853	1754
45	1855	0.989	0.927	1835	1720
46	1836	0.987	0.915	1813	1680
47	1815	0.985	0.900	1787	1634
48	1790	0.982	0.884	1758	1582
49	1762	0.979	0.865	1725	1524
50	1731	0.975	0.843	1687	1459
51	1697	0.970	0.819	1646	1389
52	1659	0.965	0.792	1601	1314
53	1619	0.958	0.762	1551	1233
54	1575	0.951	0.729	1498	1148
55	1528	0.942	0.694	1440	1060
56	1478	0.932	0.656	1378	969
57	1425	0.920	0.616	1311	878
58	1369	0.906	0.574	1241	786
59	1310	0.891	0.531	1166	696
60	1247	0.873	0.488	1088	609
61	1181	0.852	0.445	1007	526
62	1113	0.829	0.403	923	449
63	1041	0.803	0.362	836	377
64	966	0.775	0.323	748	313
65	888	0.743	0.287	660	255
66	807	0.709	0.253	572	204
67	723	0.672	0.222	486	160
68	636	0.633	0.193	402	123
69	546	0.592	0.168	323	92
70	452	0.549	0.145	249	66
71	356	0.506	0.125	180	44
72	257	0.463	0.107	119	28
73	154	0.421	0.092	65	14
74	49	0.379	0.078	19	4
75	0	0.339	0.067	0	0
76	0	0.302	0.057	0	0
77	0	0.267	0.048	0	0
78	0	0.234	0.041	0	0
79	0	0.205	0.035	0	0
80	0	0.178	0.029	0	0

^†Predicted values (loess fit). From Jan 2005 to Dec 2009 adults were interviewed once or twice per week about time allocation and production for each co-resident individual over age 6 during the previous 2 days (n = 1245 individuals from 11 villages).

^‡Predicted from binary logistic regression of whether one still hunts on thoracic vertebral body fracture status (i.e. grade ≥1; vs. none) and age.
^§Derived by multiplying value in column A by value in column B.

^¶Derived by multiplying value in column A by value in column C.

Appendix 1—table 5

Tsimane men’s age-specific daily hunting production by thoracic vertebral body fracture status and thoracic vertebral body bone mineral density (BMD).

For illustrative purposes we report estimates holding BMD at +1 SD and −1 SD of the mean.

Age (years)	(A) Hunt cals/day^*	(B) Probability still hunting: no fracture and +1 SD BMD^†	(C) Probability still hunting: no fracture and −1 SD BMD^†	(D) Probability still hunting: fracture and +1 SD BMD^†	(E) Probability still hunting: fracture and −1 SD BMD^†	(F) Hunt cals/day: no fracture and +1 SD BMD^‡	(G) Hunt cals/day: no fracture and −1 SD BMD^§	(H) Hunt cals/day: fracture and +1 SD BMD^¶	(I) Hunt cals/day: fracture and −1 SD BMD^**
40	1872	0.996	0.990	0.971	0.930	1865	1853	1819	1741
41	1884	0.995	0.988	0.967	0.920	1875	1862	1822	1732
42	1888	0.995	0.987	0.962	0.908	1878	1863	1816	1714
43	1882	0.994	0.984	0.956	0.895	1870	1853	1800	1684
44	1870	0.993	0.982	0.950	0.880	1857	1836	1776	1646
45	1855	0.992	0.979	0.942	0.864	1840	1816	1747	1602
46	1836	0.990	0.976	0.933	0.845	1819	1792	1714	1552
47	1815	0.989	0.972	0.924	0.825	1795	1764	1676	1497
48	1790	0.987	0.968	0.913	0.802	1767	1732	1633	1436
49	1762	0.985	0.963	0.900	0.778	1736	1697	1586	1371
50	1731	0.983	0.957	0.886	0.751	1701	1657	1533	1301
51	1697	0.980	0.951	0.870	0.723	1664	1614	1476	1226
52	1659	0.977	0.943	0.852	0.692	1621	1565	1414	1148
53	1619	0.974	0.935	0.833	0.660	1576	1514	1348	1068
54	1575	0.970	0.925	0.811	0.626	1527	1458	1278	986
55	1528	0.965	0.915	0.788	0.591	1474	1397	1203	902
56	1478	0.960	0.902	0.762	0.554	1418	1334	1126	819
57	1425	0.953	0.888	0.734	0.518	1359	1266	1046	738
58	1369	0.946	0.873	0.704	0.481	1296	1195	964	658
59	1310	0.938	0.856	0.672	0.444	1229	1121	881	582
60	1247	0.929	0.836	0.639	0.408	1159	1043	797	509
61	1181	0.919	0.815	0.604	0.373	1085	963	714	440
62	1113	0.907	0.792	0.568	0.339	1010	881	633	377
63	1041	0.894	0.766	0.532	0.307	931	798	554	319
64	966	0.879	0.739	0.495	0.276	849	714	478	267
65	888	0.862	0.709	0.458	0.248	766	630	407	220
66	807	0.844	0.678	0.422	0.221	681	547	340	178
67	723	0.823	0.645	0.386	0.197	595	466	279	142
68	636	0.801	0.610	0.352	0.174	509	388	224	111
69	546	0.776	0.575	0.319	0.154	424	314	174	84
70	452	0.750	0.538	0.288	0.136	339	243	130	61
71	356	0.721	0.501	0.258	0.119	257	178	92	42
72	257	0.690	0.464	0.231	0.105	177	119	59	27
73	154	0.658	0.428	0.206	0.092	101	66	32	14
74	49	0.624	0.392	0.183	0.080	31	19	9	4
75	0	0.588	0.358	0.162	0.070	0	0	0	0
76	0	0.552	0.324	0.143	0.061	0	0	0	0
77	0	0.515	0.293	0.125	0.053	0	0	0	0
78	0	0.479	0.263	0.110	0.046	0	0	0	0
79	0	0.442	0.236	0.096	0.040	0	0	0	0
80	0	0.406	0.210	0.084	0.035	0	0	0	0

^*Predicted values (loess fit). From Jan 2005 to Dec 2009 adults were interviewed once or twice per week about time allocation and production for each co-resident individual over age 6 during the previous 2 days (n = 1245 individuals from 11 villages).

^†Predicted from binary logistic regression of whether one still hunts on thoracic vertebral body fracture status (i.e. grade ≥1; vs. none), BMD (mg/cm³) and age (years).
^‡Derived by multiplying value in column A by value in column B.

^§Derived by multiplying value in column A by value in column C.
^¶Derived by multiplying value in column A by value in column D.

^**Derived by multiplying value in column A by value in column E.

Appendix 1—table 6

Binary logistic regression: effect of thoracic vertebral body fracture on the probability of tree chopping cessation after adjusting for age (model 1; n = 256 men).

Model 2 additionally includes as a covariate thoracic vertebral body bone mineral density (BMD). Shown are odds ratios (95% CIs); continuous variables are z-scored.

Parameter	Model 1	Model 2 (+BMD)
Any thoracic vertebral body fracture (grade ≥1; vs. none)	6.9^***(3.1–16.6)	6.8^***(3.1–16.6)
Age (years)	8.0^***(4.9–13.9)	6.8^***(4.0–12.4)
Thoracic vertebral body BMD (mg/cm³)	-----	0.75 (0.47–1.16)

AIC	183.41	183.75

^{^}p≤0.1, ^*p≤0.05, ^**p≤0.01, ^***p≤0.001 (refer to main text for FDR q-values).

Appendix 1—table 7

Binary logistic regression: effect of thoracic vertebral body fracture on the probability of weaving cessation after adjusting for age (model 1; n = 237 women).

Model 2 additionally includes as a covariate thoracic vertebral body bone mineral density (BMD). Shown are odds ratios (95% CIs); continuous variables are z-scored.

Parameter	Model 1	Model 2 (+BMD)
Any thoracic vertebral body fracture (grade ≥1; vs. none)	2.2 (0.8–6.4)	1.8 (0.6–5.4)
Age (years)	4.9^***(3.1–8.6)	3.3^***(1.8–6.6)
Thoracic vertebral body BMD (mg/cm³)	-----	0.51^{^}(0.23–1.05)

AIC	134.52	133.18

^{^}p≤0.1, ^*p≤0.05, ^**p≤0.01, ^***p≤0.001 (refer to main text for FDR q-values).

Appendix 1—table 8

Self-reported reasons for weaving cessation by thoracic vertebral body fracture status.

Shown are percentages of women reporting a given reason.

Reason for weaving cessation	Fracture (n = 9)	No fracture (n = 24)	Total (n = 33)
Problem with hips	100	100	100
Problem with back	100	100	100
Problem with fingers	100	100	100
Problem with hands (other than fingers)	100	100	100
Any problem with hips, back, or hands	100	100	100
Difficulty sitting	100	100	100
Difficulty seeing	89	88	88

^{^}p≤0.1, ^*p≤0.05, ^**p≤0.01, ^***p≤0.001 (χ² or Fisher’s Exact test [vs. no fracture]).

Appendix 1—table 9

Binary logistic regression: effect of thoracic vertebral body fracture on the probability of not being able to walk a full day after adjusting for age and sex (model 1; n = 493 adults).

Model 2 additionally includes as a covariate thoracic vertebral body bone mineral density (BMD). Shown are odds ratios (95% CIs); continuous variables are z-scored. Interaction terms between sex and either fracture, age or BMD do not yield significant parameter estimates and are not shown.

Parameter	Model 1	Model 2 (+BMD)
Any thoracic vertebral body fracture (grade ≥1; vs. none)	8.2^***(4.8–14.5)	7.8^***(4.5–13.8)
Age (years)	4.0^***(3.1–5.4)	3.4^***(2.4–4.8)
Sex = male	0.19^***(0.11–0.31)	0.21^***(0.12–0.34)
Thoracic vertebral body BMD (mg/cm³)	-----	0.77^{^}(0.57–1.03)
AIC	479.60	478.52

^{^}p≤0.1, ^*p≤0.05, ^**p≤0.01, ^***p≤0.001 (refer to main text for FDR q-values).

Appendix 1—table 10

Self-reported reasons for hunting cessation by thoracic vertebral body fracture status.

Shown are percentages of men reporting a given reason.

Reason for hunting cessation	Fracture (n = 34)	No fracture (n = 22)	Total (n = 56^†)
Problem with hips	29^**‡	0	18
Problem with back	53	59	55
Problem with arms	12	23	16
Problem with legs	56	55	55
Any problem with hips, back, or limbs	77	86	80
Feels weak	29^{^}	50	38
Tires easily	59	64	61
Tires easily or feels weak	65	77	70
Difficulty hearing	38	50	43
Difficulty seeing	62	77	68
Difficulty hearing or seeing	65	82	71

^{^}p≤0.1, ^*p≤0.05, ^**p≤0.01, ^***p≤0.001 (χ² or Fisher’s Exact test [vs. no fracture]).

^†Fracture data are missing for one man. For another man self-reported data are missing.
^‡FDR q = 0.012.

Note: only q-values ≤0.05 are reported.

Appendix 1—table 11

Self-reported reasons for tree chopping cessation by thoracic vertebral body fracture status.

Shown are percentages of men reporting a given reason.

Reason for tree chopping cessation	Fracture (n = 41)	No fracture (n = 35)	Total (n = 76^†)
Problem with hips	29^*‡	9	20
Problem with back	59	71	64
Problem with arms	66^{^}	83	74
Problem with legs	29	26	28
Any problem with hips, back, or limbs	83	94	88
Feels weak	54	54	54
Tires easily	63	71	67
Tires easily or feels weak	80	83	82

^{^}p≤0.1, ^*p≤0.05, ^**p≤0.01, ^***p≤0.001 (χ² or Fisher’s Exact test [vs. no fracture]).

^†Fracture data are missing for one man. For another man self-reported data are missing.
^‡FDR q = 0.036.

Note: only q-values ≤0.05 are reported.

Appendix 1—table 12

Self-reported reasons for inability to walk all day by thoracic vertebral body fracture status.

Shown are percentages of adults (pooled sexes) reporting a given reason.

Reason for inability to walk all day	Fracture (n = 95)	No fracture (n = 134)	Total (n = 229^†)
Problem with hips	39	39	39
Problem with back	61	69	66
Problem with arms	8	8	8
Problem with legs	81	86	84
Any problem with hips, back, or limbs	88	93	91
Feels weak	29	31	31
Tires easily	71	60	65
Tires easily or feels weak	76	69	72

^{^}p≤0.1, ^*p≤0.05, ^**p≤0.01, ^***p≤0.001 (χ² or Fisher’s Exact test [vs. no fracture]).

^†Fracture data are missing for one adult.

Additional files

Transparent reporting form: https://cdn.elifesciences.org/articles/62883/elife-62883-transrepform-v2.pdf
Download elife-62883-transrepform-v2.pdf

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Article PDF

Open citations (links to open the citations from this article in various online reference manager services)

Mendeley

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

Jonathan Stieglitz
Paul L Hooper
Benjamin C Trumble
Hillard Kaplan
Michael D Gurven

(2020)

Productivity loss associated with functional disability in a contemporary small-scale subsistence population

eLife 9:e62883.

https://doi.org/10.7554/eLife.62883

Share this article

Cite this article

Tsimane women weaving bags used for carrying diverse objects (left panel; photo credit: Jonathan Stieglitz) and ground mats used for resting (right panel; photo credit: Arnulfo Cary).

Top: Proportion of Tsimane men with thoracic vertebral body fracture (grade ≥1) by age, estimated using the loess function.

Top: Proportion of Tsimane women with thoracic vertebral body fracture (grade ≥1) by age, estimated using the loess function.

Top: Age-specific productivity (kcals/day) for hunting by men’s fracture status, and for fishing (all men).

Top: Age-specific productivity (kcals/day) for hunting by men’s fracture status and bone mineral density (BMD), and for fishing (all men).

A conceptual model linking somatic condition to economic productivity during aging in small-scale subsistence societies.

Percentage of men (95% CI) who completely ceased hunting by age and thoracic vertebral body fracture status.

Percentage of men (95% CI) who completely ceased tree chopping by age and thoracic vertebral body fracture status.

Percentage of women (95% CI) who completely ceased weaving by age and thoracic vertebral body fracture status.

Percentage of adults (95% CI) who are unable to walk a full day by age and thoracic vertebral body fracture status.

Descriptives for study variables*.

Percentage of men (95% CI) who completely ceased hunting by age and thoracic vertebral body fracture status (fracture grade ≥2).

Binary logistic regression: effect of thoracic vertebral body fracture on the probability of hunting cessation after adjusting for age (model 1; n = 256 men).

Tsimane men’s age-specific daily hunting production by thoracic vertebral body fracture status.

Tsimane men’s age-specific daily hunting production by thoracic vertebral body fracture status and thoracic vertebral body bone mineral density (BMD).

Binary logistic regression: effect of thoracic vertebral body fracture on the probability of tree chopping cessation after adjusting for age (model 1; n = 256 men).

Binary logistic regression: effect of thoracic vertebral body fracture on the probability of weaving cessation after adjusting for age (model 1; n = 237 women).

Self-reported reasons for weaving cessation by thoracic vertebral body fracture status.

Binary logistic regression: effect of thoracic vertebral body fracture on the probability of not being able to walk a full day after adjusting for age and sex (model 1; n = 493 adults).

Self-reported reasons for hunting cessation by thoracic vertebral body fracture status.

Self-reported reasons for tree chopping cessation by thoracic vertebral body fracture status.

Self-reported reasons for inability to walk all day by thoracic vertebral body fracture status.

Transparent reporting form

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)