Somatic health in the Indigenous Sami population - a systematic review

Figures & data

Figure 1. PRISMA flow chart showing numbers of included and excluded studies

Figure 2. Circle chart of excluded articles, categorised by country

Table 1. Summary of studies concerning the somatic health of the Sami people included in the review

Author publication year	Country/ setting	Study design	Study population/ response rate	Subjects(n)/ age	Outcome measures	Findings	Quality score	Author conclusions	Comment
Abrahamsson A et al., 2013	Sweden/ Counties of Norrbotten, Jämtland or Stockholm	Cross-sectional Questionnaire	Sami pop/ 53,4% Non-Sami pop/ 57,7% Reindeer herders/ non- reindeer herders	n = 613/ mean age 49,9 n = 525/ mean age 48,0 n = 116/ mean age 52,1 n = 493/ mean age 49,3	Self-reported health (SRH) Sence of coherence (SOC)	Reindeer-herding Sami, lower SOC than non-herding Sami. ”Healthy” 68,4% non-herders 62.4% herders 75.9% non-Sami 67.3% Sami Not statistically significant.	3(6)	Age, health and predictors of SOC are related to the reindeer husbandry life and belonging to their community	Electoral register of the Sami Parliament
Ahlm K et al., 2010	Sweden	Cohort Register-based	Members of reindeer-herding Sami families n = 7482	n = 158/ mean age 47	Unnatural deaths	37% vehicle accidents whereof 50% were alcohol affected. 23% suicides	4(8)	Improve safety of transportation and change alcohol behaviour can prevent accidents.	Reindeer-herders/owners from occupational register of Statistics Sweden and national register of reindeer herding enterprises. Spouses and children from the kinship register of Statistics Sweden
Bakken K et al., 2006	Norway The Saminor 1 study (2003–2004)	Cross-sectional Questionnaire	Sami and non-Sami/ 60%	n = 12 378 36–79 years	Insomnia	Lower prevalence of insomnia compared to non-Sami	3(6)	The results may be due to differences in attitudes to sleep as a phenomena among the Sami	Sami language criteria and self-identification
Broderstad AR et al., 2011	Norway The Saminor 1 study (2003–2004)	Cross-sectional Questionnaire	Sami and non-Sami/ 61%	n = 16 323 36–79 years	Iron status; serum-ferritin transferrin saturation obesity	Reindeer pattern; Higher Mean transferrin saturation & s-ferritin More individuals with overweight and obesity.	4(6)	High levels of s-ferritin may be due to high intake of reindeer meat. Overweight and obesity is associated with s-ferritin levels.	Sami language criteria and self-identification Article focus on iron stores in relation to dietary patterns; 5 dietary patterns whereof 1 “reindeer pattern”
Broderstad AR et al., 2007	Norway The Saminor 1 study (2003–2004)	Cross-sectional Questionnaire	Sami and non-Sami/ 54,8 % Inland vs coastal	n = 14 873 36–79 years	Iron status; serum-ferritin transferrin saturation	Higher mean s-ferritin and transferrin saturation in inland Sami compared to coastal Sami/non-Sami	4(6)	Differences in iron levels might be due to nutritional habits. Probably no differences in iron metabolism between Sami and non-Sami.	Sami language criteria and self-identification
Broderstad AR & Melhus M, 2016	Norway The Saminor 1 study (2003–2004)	Cross-sectional Questionnaire Non-fasting blood samples Physical tests	Sami and non-Sami/ 61%	n = 15 112 36–79 years	Metabolic syndrome(MetS) Diabetes Mellitus BMI	High Mets prevalence in both groups. No ethnic differences in diabetes prevalence but in received treatment. Higher mean BMI among Sami.	4(6)	Culture and linguistic specific preventive actions in the healthcare systems is important to improve health status in the whole population.	Sami language criteria and self-identification Sami affiliation 34%
Brustad M et al., 2008	Norway The Saminor 1 study (2003–2004)	Cross-sectional Questionnaire	24 municipalities in Norway divided into coastal and inland residences 5–10% reported to be Sami in the 1970 Census 61% response rate	n = 12,811 36–79 years mean age 54.6	Self-perceived health BMI	54.4–56.5% reported good health According to BMI more than 70% was classified as overweight	4(6)	5 dietary pattern were identified and characterised by additional life-style factors.	Sami language criteria and self-identification Ethnicity divided into 4 groups. Sami affiliation 33% Article focus on dietary patterns and its association to self- perceived health, ethnicity, life-style and demographic factors
Brustad M et al., 2009	Norway	Register-based retrospective cohort 1991–2006	Inside/outside SUF area Coastal/inland residence	Calculated per 1000 subjects per 5 years	Mortality	Mortality rates were similar between geographical areas with low and high density of Sami	7(8)	The risk of mortality has a homogenous pattern across ethnic groups but there are indications of differences in infant mortality.	SUF = Sami Development Fund
Daerga L et al., 2004	Sweden	Prospective cohort Questionnaire Clinical examinations Interviews	Reindeer herding Sami/ 60%	n = 51 26 men/ mean age 50.2 25 women/ mean age 49.6	Work-related musculoskeletal pain (MSP)	MSP were prevalent. High exposure of vehicle the main cause among men and psycho-social risk factors among women	0(8)	Implementing of an intervention programme may reduce the severity of MSP symptoms among reindeer herders.	2-year intervention prevention programme
Daerga L et al., 2008	Sweden	Questionnaire Cross-sectional	Reindeer herding (RH) family members/Swedish reference population Response rate 67.3%	n = 99 56 men 43 women Adults over 18 years	Physical function General health	RH scored higher on physical function than the reference population, but lower on general health scales.	4(6)	The health-related quality of life was similar compared to a Swedish reference population.	Data from 7 reindeer-herding communities Article focus on quality of life related to physical, psychosocial and socioeconomic conditions.
Eckhoff C et al., 2014	Norway	Cross-sectional Questionnaire 2003–2005	4881 Sami youths /non Sami youths 10% indigenous Sami Response rate 83%	n = 4881/ 15–16 years	Musculoskeletal pain (MSP)	High prevalence of MSP, higher among females. 22,4% reported 3–4 pain sites	3(6)	No difference in MSP between Sami and non-Sami	The Norwegian Arctic Adolescent Health Study (NAAHS)
Edin-Liljegren A et al., 2004	Sweden	Retrospective cohort	Sami Reindeer-herding Sami (RH) Non-Reindeer herding Sami Controls	n = 611 n = 170 n = 441 n = 1222 30,40,50, 60 years of age	Cardiovascular disease (CVD)	Similar risk factor patterns between Sami and non-Sami in developing CVD. RH men had lower blood pressure, higher job demands, and were more physically active.	5(8)	Different exposure to psychosocial- and behaviour risk factors partly explained the differences, which suggests are related to working conditions and lifestyle factors.	Cohort constructed from national population registers. Data from CVD preventive programme 1990–2001. Article focus on risk factors.
Eliassen BM et al., 2013	Norway The Saminor 1 study (2003–2004)	Cross-sectional Questionnaire	Sami	N = 4027 36–79 years	CVD	Marginalised Sami living in Norwegian dominated areas were more likely to report cardiovascular diseases than non-marginalised Sami living in Sami majority areas.	4(6)	The exposure to chronic stress following marginalisation were suggested as a plausible explanation.	Sami language criteria and self-identification
Eliassen BM et al., 2014	Norway The Saminor 1 study (2003–2004)	Cross-sectional Questionnaire Clinical examinations	Sami non-Sami/ 60.9%	N = 15,206 36–79 years	Angina pectoris symptoms (APS) Self-reported Angina (SRA)	APS and SRA more prevalent in Sami compared to non-Sami.	4(6)	In women, less moderate alcohol consumption and leisure time physical activity in Sami may explain the ethnic difference.	Sami language criteria and self-identification
Eliassen BM et al, 2015	Norway The Saminor 1 study (2003–2004)	Cross-sectional Questionnaire	Sami non-Sami/ 60.9%	N = 15,206 36–79 years	Myocardial infarction(SMI)	No ethnic differences in SMI	4(6)	Similar living conditions and close interactions between ethnics groups may explain the findings.	Sami language criteria and self-identification
Eriksen AMA et al., 2016	Norway The Saminor 2 study	Cross-sectional Questionnaire	Sami non-Sami/ 27%	N = 11,130 2167 Sami 8963 non-Sami 18–69 years	Chronic pain(ChP)	Chronic pain; Sami men 48.5% Sami women 52.8%	3(6)	Childhood violence was associated with adult ChP & increased number of pain sites.	Sami language criteria and self-identification 19.5% Sami residents Article focus on association between childhood violence and chronic pain.
Hansen KL et al., 2010	Norway The Saminor 1 study (2003–2004)	Cross-sectional Questionnaire	Sami non-Sami Sami 33.1% Kven 7.8% Norwegian 59.1%	n = 12 265 36–79 years	Self-reported health	Poor health; Sami men 28.8–31.4% Sami women 32.9–35.4% Sami reports poorer health than the Norwegian population. Women reports poorer health than men.	3(6)	Self-reported ethnic discrimination and low socio-economic status contributes to the inequalities.	Sami were grouped according to their Sami affiliation. Article focus on discrimination and ethnicity.
Harbo HF et al., 2007	Norway	Clinical examinations Blood samples	Sami Sami controls non-Sami controls	n = 12 n = 200 n = 312	Multiple sclerosis (MS)	Lower prevalence of MS among Sami	4(8)	Low frequency of MS-associated haplotype together with genetic and environmental factors may contribute to the findings.	Sami language criteria and identified in clinical settings or in questionnaire.
Hassler S et al., 2005	Sweden	Register-based Cohort	Constructed Sami cohort, non-Sami reference population	N = 41,721 7482 reindeer-herding Sami/34,239 non-herding Sami non-Sami ref pop 4 times larger	Standard mortality ratio (SMR) Life expectancy Death causes	Lower SMR for cancer and a higher SMR for injuries with external causes in Sami men Higher SMRs for diseases of the circulatory and respiratory systems in Sami women, compared to ref pop.	7(8)	Similarities in mortality patterns due to close interactions between ethnic groups. Differences may be explained by lifestyle, psychosocial and/or genetic factors.	National kinship register. Occupational register of Statistics Sweden 1960–1990. National register of Reindeer enterprises. Electoral register of the Sami Parliament 1993 and 1997.
Hassler S et al., 2008	Sweden	Register-based Cohort	Constructed Sami cohort, non-Sami reference population	N = 41,721 7482 reindeer-herding Sami/34,239 non-herding Sami non-Sami ref pop 4 times larger	Cancer	Sami women; higher risk for stomach- and ovaries cancer. Lower risk for bladder cancer. Sami men; higher risk for stomach cancer lower risks for colon-, prostate cancer, malignant melanoma and non-Hodgkins lymphoma.	7(8)	The differences are suggested to be related to traditional Sami lifestyle factors, for example diet and physical activity, as protective factors from developing cancer.	National kinship register. Occupational register of Statistics Sweden 1960–1990. National register of Reindeer enterprises. Electoral register of the Sami Parliament 1993 and 1997.
Naseribafrouei A et al., 2016	Norway The Saminor 1 study (2003–2004)	Cross- sectional Questionnaire Non-fasting blood samples	Sami non-Sami/ 60,9%	N = 15,208 36–79 years	Pre-diabetes(PD) Diabetes mellitus (DM)	PD Sami; men 3.4% women 2,7% DM Sami; men 5,5% women 4,8%	4(6)	Heterogeneity in the prevalence of PD and DM in different geographical regions and between different ethnic groups	Sami; language criteria and self-identification
Nystad T et al., 2010	Norway The Saminor 1 study (2003–2004)	Questionnaire Clinical examination	Sami non-Sami/ 57.3%	n = 15 546 36–79 years	Obesity BMI	High prevalence of obesity. Sami women more obese than Norwegian women. Sami men less obese than Norwegian men.	5(6)	More studies are needed to examine if the ethnic differences are due to dietary habits and/or physical activities.	Sami language criteria and self-identification
Omma L et al., 2012	Sweden	Cross-sectional Questionnaire	Sami youths 59%	n = 516 18–28 years	Self-reported health Headache	95.3% felt healthy 72,3% men 63,3% women Often headaches men 4,6% women 13,2%	3(6)	Young Sami had good health. Physical health in young Sami may be better than in young Swedes.	Sami Educational Centre Jokkmokk, Sami parliament electoral register, Reindeer-owner register, the Sami youth organisation, 24 Sami organisations. Article focus mental health.
Omma L et al, 2015	Sweden	Cross-sectional Questionnaire	Sami children 12–18 years 70%	n = 121 12–18 years	Health-related quality of life (HRQOL) Physical wellbeing	30–40% reported low-functioning and well-being. High physical wellbeing was reported by 27%.	5(6)	Those with an explicit Sami identity reported low HRQOL in some aspects. Ethnicity-relative negative treatments partly explain the lower HRQOL.	Sami school programmes
Ross AB et al., 2009	Sweden	Cross-sectional Questionnaire Clinical measurements	Reindeer-herding Sami (RS) Non-reindeer herding Sami (NRS) non-Sami controls (NS)	n = 145 n = 450 n = 1000 Mean age 42–47.4 years	Blood glucose Blood pressure Physical activity BMI	RS women lower plasma glucose. RS men lower diastolic blood pressure. RS higher physical activity to NRS. BMI 25,2–26,2	3(6)	No significant difference of BMI among the groups. Traditional lifestyle defined by occupation is reflected in food and nutrient intake.	The Västerbotten Cardiovascular Intervention Programme (1990–2001) Article focus on food and nutrient intake.
Sjölander P et al., 2008	Sweden (1985–2002)	Register-based Cohort	Sami cohort Reindeer herding(RH) non-herding Sami (NH) non-Sami controls, 4 times larger	n = 15,914 n = 4465 n = 11,449 .n = 71,550	Incidence & mortality from Stroke, Subarachnoid haemorrhage (SAH) Acute myocardial infarct (AMI)	No elevated risk of developing AMI among the Sami. Higher incidences of stroke and SAH for both Sami men and women.	6(8)	Differences in incidence of stroke are caused by behavioural and psychosocial risk factors.	RH: National Occupational registers & Registers of Reindeer Breeding Enterprisers NH: Electoral registers of the Sami parliament and National Kinship registers
Sjölander P et al., 2008	Sweden	Cross-sectional Questionnaire	Reindeer herders (RH) 68% Controls; women, reindeer herding families Men, blue-collar workers	n = 74 men ≥18 years Controls; n = 53 women n = 194	Musculoskeletal symptoms	RH men symptoms in any region previous 7 days 78% 12 months 92%	5(6)	Musculoskeletal symptoms constitute a health problem in reindeer husbandry which calls for preventive actions.	Reindeer-herding communities 1 Jämtland 3 Västerbotten 4 Norrbotten
Soininen L et al., 2008	Finland Municipalities of Inari and Utsjoki (1979–2005)	Retrospective cohort	Sami* non-Sami ”mixed” Sami *Sami classified as a person with at least 75% of any ethnic group of Sami	n = 2091 n = 4161	Mortality	Cancer mortality is low. Accidents and suicides are common.	6(8)	The total mortality rates of the Sami do not differ from that of the general population. The Sami men had a lower disease mortality compared with the Finnish population	National population register; Sami classification by interview Sami persons to identify language and from studying genealogical sources.
Soininen L et al., 2012	Finland Municipalities of Inari and Utsjoki (1979–2009)	Retrospective cohort	Cancer patients; Sami non-Sami “mixed” Controls; Finnish patients outside the cohort	n = 2091 n = 4161 n = 20 181	Cancer patients survival in rural areas compared to average Finnish cancer patients	Sami; 204 cancer cases non-Sami;391 cancer cases	6(8)	No difference between the cancer survival in the different groups. Long distances to medical care or Sami ethnicity have no influence of the cancer survival	Sami identified by material of the Finnish International Biological programme which were based on interview and by genealogical sources
Spein AR et al., 2013	Norway The Norwegian Arctic Adolescent Health study (2003–2005)	Cross-sectional Questionnaire	Sami youths 10th-11th graders	n = 350	Self-reported health (SRH)	89% of the Sami youth reported good or very good health	3(6)	Physical activity was protective for good SRH. Suicidal thoughts were risk factors associated with poor SRH.	Sami; Objective questions of ethnicity and language and subjective questions of self-identification
Storm C et al., 2006	Sweden The municipalities of Gällivare and Kiruna	Cross-sectional Questionnaire	Sami women 21–70 years 65%	N = 487	Neck-shoulder pain (NSP) Temporomandibular disorders (TMD) Headache Self-reported health	Prevalence: NSP 56%, TMD 32%, Headache 61% Good health 86%	4 (6)	Musculoskeletal symptoms are common among an adult sample of Sami women. Comorbidity between symptoms was found.	Electoral register of the Sami parliament or registered as reindeer herders/owners in the Swedish Board of Agriculture.
Storm C et al., 2007	Sweden The municipalities of Gällivare and Kiruna	2-year follow up Questionnaire Clinical case-control study	Sami women	n = 68 mean age 48.7	Neck-shoulder pain (NSP) Temporomandibular disorders (TMD) Headache BMI	Annual incidence rate TMD 6.5% Cases has higher BMI (28.2) than controls (25.4)	7(8)	Severe TMD symptoms remained unchanged over the 2-year follow-up and was related to impaired general health and awareness of oral para-functions.	Electoral register of the Sami parliament or registered as reindeer herders/owners in the Swedish Board of Agriculture.