942153027360J AgromedicineJournal of Agromedicine1059-924X1545-081322191505329768010.1080/1059924X.2012.626750NIHMS357592ArticleA Cross-sectional Exploration of Excessive Daytime Sleepiness, Depression and Musculoskeletal Pain among Migrant FarmworkersSandbergJoanne C.PhD1GrzywaczJoseph G.PhD1TaltonJennifer W.MS2QuandtSara A.PhD3ChenHaiyingPhD4ChatterjeeArjun B.MD5ArcuryThomas A.PhD1Department of Family and Community Medicine, Wake Forest School of Medicine, Center for Worker Health, Wake Forest School of MedicineDepartment of Biostatistical Sciences, Division of Public Health Sciences, Wake Forest School of MedicineDepartment of Epidemiology and Prevention, Division of Public Health Sciences, Wake Forest School of Medicine, Center for Worker Health, Wake Forest School of MedicineDepartment of Pulmonary, Critical Care, Allergy, and Immunologic Medicine, Wake Forest School of Medicine, Center for Worker Health, Wake Forest School of MedicineDepartment of Biostatistical Sciences, Division of Public Health Sciences, Wake Forest School of Medicine, Center for Worker Health, Wake Forest School of MedicineAddress correspondence to: Thomas A. Arcury, Ph.D., Department of Family and Community Medicine, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, Phone: 336-716-9438, Fax: 336-716-3206, tarcury@wfubmc.edu1722012120121120131717080

In this study the authors estimated the prevalence of elevated daytime sleepiness, depressive symptoms, and musculoskeletal pain among Latino migrant farmworkers, and examined the relationship among these symptoms. Data are from a cross-sectional survey of migrant farmworkers (300) conducted in eastern North Carolina in 2009.

Results

Eleven percent of Latino farmworkers reported elevated levels of daytime sleepiness, 28% reported elevated levels of depressive symptoms, and 5% reported moderate to severe musculoskeletal pain on a daily or weekly basis. Depressive symptoms and daytime sleepiness were positively associated. Depression and daytime sleepiness may increase risk of injury; further research regarding sleep issues is warranted.

DepressionExcessive Daytime SleepinessMusculoskeletalmigrantfarmworkersLatinoNational Institute of Environmental Health Sciences : NIEHSR01 ES008739-15 || ES
INTRODUCTION

Sleep disorders, depression, and musculoskeletal pain often appear as a cluster of symptoms. The presence and potential co-occurrence of these symptoms have a particular significance among the farmworker population. In addition to placing individuals at increased likelihood of developing multiple health conditions, farmworkers with sleep disorders, depression, or musculoskeletal pain may have an increased risk of experiencing workplace injuries.1,2 Working with toxic pesticides, handling sharp farm implements, and frequent bending and lifting heavy loads provide multiple opportunities for injuries to occur. Concern regarding the prevalence and association between daytime sleepiness (with excessive levels of daytime sleepiness being a symptom of multiple sleep disorders), depressive symptoms, and musculoskeletal pain among the farmworker population is therefore warranted.

Latino migrant and seasonal farmworkers live and labor under conditions that can lead to excessive daytime sleepiness, depression, and musculoskeletal pain. Farmworkers experience long hours and low pay3 and report elevated levels of injuries and illness compared to the U.S. workforce as a whole.3,4 Their work often involves bending, twisting, and lifting heavy items, activities that can lead to pain and injury.5 Use of pesticides in the fields, at times with limited training, exposes them to toxins that can result in acute and chronic pesticide poisoning and has been associated with multiple negative effects, including depression.68 Their housing is often crowded, of poor quality,3,9 and lacking in privacy 3,10 Migrant farmworkers frequently lack access to adequate health care, which may exacerbate dental and health problems.6,1115

Sleep disorders, which can lead to elevated daytime sleepiness, are often associated with depression.1619 Depressed individuals are more likely than nondepressed individuals to have elevated daytime sleepiness levels.20,21 Sleep disorders are a central component of depression, and the presence of sleep disorders places an individual at risk of developing depression.22,23

Information about the prevalence of sleep disorders and associated symptoms, including excessive daytime sleepiness, among Latinos in general,24,25 and Latino farmworkers more specifically, is scant. Researchers have noted that approximately 20% of Latino farmworkers in Starr County, Texas experienced fairly bad or very bad sleep quality.26 They also found that Latino migrant farmworkers who indicated that they had experienced poor sleep quality or were depressed were at increased risk of experiencing chronic back pain. Physically strenuous work, such as that performed by farmworkers, has also been associated with increased likelihood of sleep disturbance.27 Crowded living conditions may increase the difficulty of obtaining an adequate and uninterrupted stretch of sleep.

Elevated levels of depressive symptoms have been documented among Latino farmworkers in different regions of the country, ranging from approximately 20% in California28 to 25% to 40% in North Carolina,29,30 and 40% in the Midwest.31,32 Poor working conditions are associated with depression among Latino migrant workers in North Carolina.30 Extended separation from family members, the remote location of many farming camps, and low levels of fluency in English contribute to physical and social isolation.33

Agricultural workers experience high levels of musculoskeletal pain. Fifteen percent of farmworkers nationwide reported that they had experienced musculoskeletal pain during the previous 12 months, the percentage increasing to nearly 20% among those who had performed agricultural work for at least 10 years.14 More than 20% of Latino farmworker adults in Texas reported chronic back pain,26 and 45% of male and 75% of female Latino vineyard workers in Oregon reported experiencing musculoskeletal pain in at least one region of their body.34 Those engaged in farming activities have an increased risk of developing osteoarthritis, back pain, and knee, hand, and wrist disorders.5,35

Research on other populations indicates that sleep disorders, elevated levels of depressive symptoms, and musculoskeletal pain each appear to contribute to the risk of experiencing one or both of the other symptoms.16,3638 Physical illness and musculoskeletal pain can mimic or exacerbate depression. Furthermore, depression may delay recovery from musculoskeletal injuries, and pain may extend the time period during which one experiences depressive symptoms.39

Research that examines the association between sleep disorders, depression, and musculoskeletal pain in farmworkers is scant. This paper addresses this gap by (1) describing levels of daytime sleepiness, depressive symptoms, and musculoskeletal pain, and (2) determining empirical overlap among measures of sleepiness, musculoskeletal pain, and depressive symptoms, and (3) identifying risk factors for each health-related problem among Latino farmworkers in North Carolina.

MATERIALS AND METHODS

Data are from a cross-sectional survey of migrant farmworkers conducted in eastern North Carolina June through August, 2009. The farmworkers recruited for the study worked primarily, but not exclusively with tobacco. Primary work tasks included topping, and picking tobacco. The study protocol was reviewed and approved by the Wake Forest University Health Sciences Institutional Review Board.

Participant Recruitment

Participant recruitment and selection involved two steps: (1) sites or camps were identified and selected, and (2) workers within camps were identified and selected. Farmworker camps were located in three eastern North Carolina counties, using an approach similar to that used by Arcury and colleagues.40 A list of camps was provided by the North Carolina Farmworkers Project (Benson, NC). Camps were selected and visited in a random order from this list. The randomization process was computer-assisted.

A census was completed at the selected camps in which farmworkers provided preliminary consent to participate in the study. Latino farmworkers at each camp were recruited from the census list; no more than 6 were recruited at each camp to obtain a representative sample of farmworkers from numerous camps in the region. The overall sample size included 300 farmworkers recruited from 52 camps. Farmworkers at 62 camps were asked to participate in the study; participation was declined at eight camps and access was denied by growers at two camps. At the 52 camps included in the sample, 157 individuals refused to participate, for a participation rate of 66%. Informed consent was provided by all participants.

Data Collection

Data collection included an interviewer-administered questionnaire. Questionnaire items addressed participant demographic and background characteristics, presence of depressive symptoms during the previous week, estimates of daytime sleepiness in actual or hypothetical situations during the previous month, and the extent of musculoskeletal discomfort or pain experienced during the current season. The questionnaire was developed in English and translated into Spanish by a native Spanish speaker familiar with Mexican Spanish farmworker vocabulary. The questionnaire was pretested and modified based on feedback from farmworkers.

Measures

The analysis is based on three sets of indicators derived from the questionnaire data that measure body discomfort and pain, depressive symptoms, and levels of daytime sleepiness. Personal characteristics of the farmworkers were also recorded. Daytime sleepiness was measured with the Epworth Sleepiness Scale (ESS), a validated tool41,42 that has been used in some nonclinical studies4347 and numerous clinical studies.20,21,4850 Participants reported how likely is it that they had or would have dozed off when or if they had been in 8 distinct situations, including “watching TV” or “sitting and talking with someone” during the past month. Responses could range from “never” (0) to there being a “high chance of dozing” (3). To be considered in the ESS scale a participant had to answer a minimum of five of the eight questions. For each participant who answered the minimum number of questions, the values from each of the responses were summed, the maximum potential value being 24. Participants whose ESS score was ≥ 10 were considered to have elevated daytime sleepiness levels.20,51

Depression was measured using the Boston × 4 short form of the Center for Epidemiological Studies – Depressive Symptoms (CES-D), a 10-item form that has been demonstrated to have good predictive accuracy52 and appropriate for use among Latino immigrants.53 For each of the 10 items, participants were asked how often they felt or behaved in a particular way during the previous week: rarely or none of the time (0) to most or all of the time (3). The participants’ responses were summed, and the maximum value for the CES-D 10 item index was 30. If any of the 10 items were missing the CES-D value was set to missing. Participants with CES-D scores ≥ 10 were considered to have elevated levels of depressive symptoms.53

Participants reported if they had experienced discomfort or pain as a result of their job in eight distinct body parts (neck, shoulders, elbows, wrists, hands, lower back, knees, and ankles) during the current agricultural season using a series of questions and a scoring system adapted from the NIOSH Body Discomfort Interview Guide.54 For each body part, the frequency of pain was recorded, 0 indicating no experience of work-related discomfort or pain, 4 indicating daily discomfort or pain. A value of 1 in the version used in this study indicates that the participant reported he or she had experienced pain or discomfort at least once a month during the current season; a value of 1 in the NIOSH Guide indicates pain or discomfort within the past year at the participant’s current job. Those who reported work-related pain in a particular body part were asked to rate the severity of the pain. The values in our questionnaire ranged from no pain (0) to unbearable (4). The NIOSH Guide did not indicate a value for “no pain.” The values associated with other levels of pain were identical in the NIOSH version and the version fielded. The maximum value associated with any one body part for the individual was the value assigned to the participant. The value of the frequency of pain (0–4) was multiplied by the value of the severity of pain (0–4) for each body part. Participants with frequent moderate or severe pain in one body part therefore had a higher pain scale value than those who reported infrequent or mild musculoskeletal pain in many body parts. Participants who experienced pain on a daily or weekly basis in one or more body parts and reported moderate, severe, or unbearable pain in the same body part(s) were considered to have elevated musculoskeletal pain.

Personal characteristics of study participants were included in this analysis. Farmworkers were asked whether they spoke English, Spanish, an indigenous language, or any other language. Years spent working in agriculture in the U.S. includes the year in which the respondent was interviewed. Age, gender, and educational attainment of the participants were recorded as well.

Statistical Methods

Descriptive statistics were examined in the entire sample for farmworker characteristics of interest (gender, age, educational attainment, seasons in U.S. agriculture, and language). Descriptive statistics as well as the inter-correlations were also examined for the primary outcome variables of depression, musculoskeletal pain and daytime sleepiness. A generalized estimating equation (GEE) approach that allows adjustment of camp clustering was used to further understand the bivariate association between elevated levels of depression, daytime sleepiness, and musculoskeletal pain versus non-elevated levels in farmworker characteristics. These data analyses were performed using SAS 9.2 (SAS Institute, Cary, NC) and p-values of ≤ .05 were considered statistically significant.

RESULTS

Ninety-five percent of the sample of 300 adult farmworkers was male (Table 1). Approximately 31% of the workers were younger than 30 years old, 37% were between the ages of 30 and 39, and 32% were age 40 or older. The typical Latino farmworker had limited formal education, as over half of the participants had six years of education or less. Almost all Latino farmworkers spoke Spanish; 12% spoke English, and 20% spoke an indigenous language. Approximately 14% had been farmworkers in the U.S. for one year or less; 47% reported that they had worked in U.S. agriculture for 2 to 7 years, and 39% reported 8 or more years.

The mean ESS score was 5.10 (± 3.25). Eleven percent of the Latino farmworkers reported elevated sleepiness, as determined by an ESS score of ten or greater. The mean value of the 10-item short form of the CES-D was 7.89 (±3.22). Twenty-eight percent of the farmworkers had elevated levels of depressive symptoms, as represented by a score of 10 or more on the short version of the CES-D (Table 3). The mean value of the musculoskeletal pain scale was 1.35 (±2.09). Five percent of the farmworkers reported elevated musculoskeletal pain, indicating that they experienced weekly or daily pain that was moderate to unbearable in at least one body part during the current growing season.

Age, gender, and years in U.S. agriculture affected the prevalence of one or more conditions. Increased age was significantly associated with increased daytime sleepiness and elevated depressive symptoms. Prevalence of excessive daytime sleepiness was particularly elevated among those aged 40 and older. Women were significantly more likely than men to report elevated musculoskeletal pain, but not elevated depressive levels or elevated daytime sleepiness. A greater number of years in U.S. agriculture was significantly associated with elevated levels of daytime sleepiness, but not with elevated depressive symptoms or musculoskeletal pain. Years in U.S. agriculture was no longer significantly associated with elevated levels of daytime sleepiness when age was controlled (analysis not shown). Neither educational attainment nor language spoken had a significant association with the prevalence of any of the symptoms noted.

The level of daytime sleepiness was significantly and positively associated with depressive symptoms (0.27 at p < .001). The musculoskeletal pain value in Table 2 represents the frequency-intensity value associated with the body part reported as having the greatest level of discomfort or pain. The level of daytime sleepiness was significantly and negatively correlated with musculoskeletal pain, although the strength of the association was weak (−0.15 at p < 0.01).

DISCUSSION

This study reports the level of three symptoms among Latino farmworkers in North Carolina. To the best of our knowledge, this is the first report to examine the ESS level among a Latino farmworker population. Eleven percent of Latino farmworkers reported excessive daytime sleepiness, as indicated by an ESS score ≥ 10. Depression is a problem for a substantial number of Latino migrant and seasonal farmworkers; 28% of the Latino farmworkers in eastern North Carolina reported elevated depressive symptoms. Previous studies found that 20% to 40% of Latino farmworkers had elevated levels of depressive symptoms; the findings in this study are consistent with this prior research.29,30 Five percent of the Latino farmworkers reported pain that was moderate to severe. This prevalence of pain is less than the levels of 20% to 45% reported in other studies of agricultural workers.26,34

Although our study results for pain prevalence initially appear to be inconsistent those from other studies, it is important to note that the 5% figure represents pain that is of moderate or greater intensity experienced on a weekly to daily basis. Other studies include pain that occurs less frequently or is of lower intensity.26,34 Recall periods also vary. All farmworkers in this study, including those interviewed in June, were only asked about pain during the current season. Other studies had a longer recall period,14,26 which would be expected to increase reports of pain. The crops worked and tasks performed at different times during the season also influence musculoskeletal disorders.4,5 and may therefore affect pain reports during the data collection period of this study and across different studies. Finally, the vulnerabilty associated with being a Latino migrant farmworker in the U.S. may result in underreporting of injury and associated pain in this and other studies.5

The positive association between elevated daytime sleepiness and depressive symptoms is consistent with research of other populations.18,2022,55,56 Cross sectional studies are unable to determine causal ordering;34,56 longitudinal research suggests that depression and sleep disorders may each contribute to the presence of the other symptom.36 Having elevated depressive symptoms or a sleep disorder, as assessed by the presence of symptoms associated with a sleep disorder, increases the risk of having or developing the associated condition.

Daytime sleepiness was significantly and negatively associated with musculoskeletal pain, although the association was weak. These findings initially appear to be inconsistent with other studies that report that sleep disorder symptoms are positively associated with pain. These apparently contradictory findings may be due to use of different analytical procedures. The analyses conducted by Shipp and colleagues (2009), and Ohayon (2009) do not address the level of pain symptoms. Castro and Daltro (2008) note the high level of sleeping problems among pain clinic patients, but do not analyze the association between intensity of pain and sleep disorders. Differences in recall period, crops worked and tasks performed may also account for apparent the apparent inconsistency between results of this and other studies.

Depressive symptoms and musculoskeletal pain were not significantly correlated with each other. This initially appears to be inconsistent with studies that have reported an association between back pain and depression among the general populations or agricultural workers.2638 Shipp and colleagues’ (2009) and Xiang and colleagues’ (1999) studies of farmworkers found a positive association between depression and back pain; the measure of back pain they used included low grade pain. Our findings, in the context of existing research,16, 37,38 suggests that although pain and depressive symptoms may be associated with each other at a general level, the level of frequency and intensity of pain in one body part only is not significantly associated with increased levels of depressive symptoms. It should be noted that the report period varies across measures used in this study, ranging from the previous week (CES-D) to the past month (ESS) to the current season (musculoskeletal pain), leading to potential bias. Variation in symptoms across the agricultural season57 and inclusion of farmworkers at different times during the season, including fairly early in the season, add further room for potential bias.

Increased age placed Latino farmers at elevated risk of excessive daytime sleepiness and depression, but not musculoskeletal pain. Research on other populations is mixed, with some studies showing a positive association between age and excessive daytime sleepiness.58 Other research indicates that increased age is not associated with elevated daytime sleepiness, except among those 75 and older.47,56 Researchers have found that older agricultural workers are more likely to report musculoskeletal pain than their younger counterparts,14,26,34 findings inconsistent with our results. Intensity of pain was not, however, included in other researchers analyses and may account for the difference in findings. Consistent with other research on Latino farmworkers, women in our sample were more likely to report pain than men.26 Other associations were not significant, possibly due to the limited statistical power of the analyses.

These finding suggest that it is particularly important to screen and treat older farmworkers for elevated levels of depressive symptoms and elevated daytime sleepiness. Although they may not be at increased risk of experiencing high intensity pain, studies suggest that older agricultural workers are at increased risk of experiencing musculoskeletal pain more generally. Health care providers who diagnosis and treat Latino farmworkers should be alert to the increased risk faced by their female and older patients.

Elevated depressive symptoms, daytime sleepiness, and musculoskeletal pain pose particular health risks to farmworkers who use farm machinery and sharp tools, apply toxic pesticides, and transfer heavy loads. The presence of these conditions may be associated with an increased risk of experiencing workplace injuries.1,2 Identification of the three symptoms and treatment for the associated disorders could reduce occupational injuries among the farmworker population. The importance of identifying and effectively treating depression, sleep disorders, and musculoskeletal pain among the Latino farmworker population is therefore crucial.

Knowledge about the prevalence of sleep disorders among Latino farmworkers is limited.26 Multiple measures should be used to evaluate the presence of sleep disorders and their related symptoms, and to determine the effect of individual characteristics on the risk of having a sleep disorder among migrant farmworkers. Additional instruments that could be used include the Pittsburgh Sleep Scale,59 Berlin Sleep Apnea Questionnaire,60 and the Insomnia Severity Index.61

Attention should be given to characteristics of farmworker housing that may contribute to or detract from workers’ opportunity to obtain adequate sleep, including degree of crowding, temperature, humidity, noise level in the sleeping area, and functions for which the sleeping area is used. Furthermore, the increased level of elevated daytime sleepiness among older farmworkers suggests that researchers should examine whether the effects of housing characteristics on sleep quality may vary by the age of farmworkers.

This research adds to our knowledge about of the prevalence of elevated depressive symptoms, excessive daytime sleepiness, musculoskeletal pain, and the relationship between them among Latino farmworkers in North Carolina. There are, however, limitations to the data and analysis. The Latino farmworkers were drawn from three counties in North Carolina, limiting the generalizability of the findings to other regions, and the relatively small sample size limits the statistical power of the analysis. However, the sampling process recruited participants from 52 farmworker camps and restricted the participants from each camp, ensuring that farmworkers from diverse camps and settings were included in the analysis. The response rate of 66%, although lower than preferred, is higher than the mean response rate articles published across diverse academic disciplines.62 Finally, although the CES-D, ESS, and musculoskeletal pain questions all rely on self-reports, potentially biasing the responses, use and evaluation of these instruments (or very similar instruments) in multiple studies make them appropriate for this analysis.

A significant percentage of Latino farmworkers reported elevated depressive symptoms and, to a lesser degree, excessive daytime sleepiness. The presence of either condition may increase the risk of workplace injury. Given that the tasks associated with their workplace them at elevated risk of work injury, further research is needed to estimate the prevalence of sleep disorders among migrant farmworkers and to examine factors that contribute to sleep disorders, and the resulting daytime sleepiness, among this population.

Grant sponsor: Northeast Center for Agricultural and Occupational Health, with support from the National Institute for Occupational Safety and Health (grant number U50OH007542-09), and by grant R01-ES008739 from National Institute of Environmental Health Sciences.

The authors greatly appreciate the help of the North Carolina Farmworkers Project (Benson, NC) and Rebecca Crain, Department of Epidemiology and Prevention, Wake Forest School of Medicine, with sample recruitment and collection.

VoaklanderDCUmbarger-MackeyMLWilsonMLHealth, medication use, and agricultural injury: a reviewAm J Ind Med2009521187688919731241LindbergECarterNGiglasonTJansonCRole of snoring and daytime sleepiness in occupational accidentsAm J Respir Crit Care Med2001164112031203511739131KandelWProfile of Hired Farmworkers, A 2008 UpdateEconomic Research Report No 60Economic Research Service. U.S. Department of Agriculture2008Available at: http://www.ers.usda.gov/publications/err60/err60.pdfAccessed April 4, 2011Center for Disease ControlWorker Health Chartbook, 2004National Institute for Safety and Occupational HealthNIOSH Report 2004-146Available at: http://www.cdc.gov/niosh/docs/2004-146/ch3/ch3-1.asp.htmAccesssed April 4, 2011DavisKGKotowskiSEUnderstanding the ergonomic risk for musculoskeletal disorders in the United States agricultural sectorAm J Ind Med200750750151117506508VillarejoDMcCurdySABadeBSamuelsSLighthallDWilliamsDThe health of California’s immigrant hired farmworkersAm J Ind Med201053438739720191600GrzywaczJGQuandtSAVallejosQMWhalleyLEChenHIsomSBarrDBArcuryTAJob demands and pesticide exposure among immigrant Latino farmworkersJ Occup Health Psychol201015325226620604632BeselerCLStallonesLStructural equation modeling of the relationships between pesticide poisoning, depressive symptoms, and safety behaviors among Colorado farm residentsJ Agromedicine2006113–4354619274896ZiebarthAHousing seasonal workers for the Minnesota processed vegetable industryRural Sociol2006712335357VallejosQMQuandtSAGrzywaczJGIsomAChenHGalvanLWhalleyLEChatterjeeABArcuryTAMigrant farmworkers’ housing characteristics across an agricultural season in North CarolinaAm J Ind MedForthcomingCarrollDSamardickRMBernardSGabbardSHernandezTFindings from the National Agricultural Workers (NAWS) 2001–2002: A demographic and employment file of United States farmworkersResearch Report No 9US Department of Labor2005Available at: http://www.doleta.gov/agworker/report9/naws_rpt9.pdfArcuryTAQuandtSADelivery of health services to migrant and seasonal farmworkersAnnu Rev Public Health20072834536317291182QuandtSAClarkHMRaoPArcuryTAOral health and quality of life of migrant and seasonal farmworkers in North CarolinaJ Agric Saf Health2007131455517370913National Institute for Occupational Safety and HealthOccupational Health of Hired Farmworkers in the United States: National Agricultural Workers Survey Occupational Health Supplement, 1999NIOSH Publication No 2009-1192009Available at: http://www.cdc.gov/niosh/docs/2009-119/pdfs/Book%202%20508v2.pdfAccessed April 4, 2011EmmiKEJurkowskiJMCodruNBellEMKacicaMACarterTPAssessing the health of migrant and seasonal farmworkers in New York State: Statewide Data 2003–2005J Health Care Poor Underserved201021244846320453349OhayonMMSchatzbergAFUsing chronic pain to predict depressive morbidity in the general populationArch Gen Psychiatry2003601394712511171CastroMMCDaltroCSleep patterns and symptoms of anxiety and depression in patients with chronic painArq Neuropsiquiatr2009671252819330205BreslauNRothTRosenthalLAndreskiPDaytime sleepiness: An epidemiological study of young adultsAm J Public Health19978710164916539357347BixlerEOVgontzasANLinHMCalhounSLVela-BuenoAVKalesAExcessive daytime sleepiness in a general population sample: the role of sleep apnea, age, obesity, diabetes, and depressionJ Clin Endocrinol Metab20059084510451515941867StroeAFRothTJeffersonCComparative levels of excessive daytime sleepiness in common medical disordersSleep Med201011989089620817600IshmanSLCaveyRMMettelTLGourinCGDepression, sleepiness, and disease severity in patients with obstructive sleep apneaLaryngoscope2010120112331233520939075OhayonMMEpidemiology of insomnia: what we know and what we still need to learnSleep Med Rev2002629711112531146RiemannDInsomnia and comorbid psychiatric disordersSleep Med20078 Supplement 4S15S2018346672BaronKGLiuKAChanCLShaharEHasnain-WyniaRZeePRace and ethnic variation in excessive daytime sleepiness: the multi-ethnic study of atherosclerosisBehav Sleep Med20108423124520924836LoredoJSSolerXBardwellWAncoli-IsraelSDimsdaleJEPalinkasLASleep health in US Hispanic populationSleep201033796296720614856ShippEMCooperSPdel JuncoDJDelclosGLBurauKDTortoleroSWhitsorthREChronic back pain and associated work and non-work variables among farmworkers from Starr County, TexasJ Agromedicine2009141223219214853ÅkerstedtTFredlundPGillbergMJanssonBA prospective study of fatal occupational accidents – relationship to sleeping difficulties and occupational factorsJ Sleep Res2002111697111869429AldereteEVegaWAKolodyBAguilar-GaxiolaSDepressive symptomatology: prevalence and psychosocial risk factors among Mexican migrant farmworkers in CaliforniaJ Community Psychol1999274457471GrzywaczJGQuandtSAChenHIsomSKiangLVallejosQArcuryTADepressive symptoms among Latino farmworkers across the agricultural season: structural and situational influencesCultur Divers Ethnic Minor Psychol201016333534320658876HiottAEGrzywaczJGDavisSWQuandtSAArcuryTAMigrant farmworker stress: mental health implicationsJ Rural Health2008241323918257868HoveyJDMagañaCAcculturative stress, anxiety, and depression among Mexican immigrant farmworkers in the Midwest United StatesJ Immigr Health20002311913116228745MagañaCGHoveyJDPsychosocial stressors associated with Mexican migrant farmworkers in the Midwest United StatesJ Immigr Health200352758614512761GrzywaczJGQuandtSAEarlyJTapiaJGrahamCNArcuryTALeaving family for work: ambivalence and mental health among Mexican migrant farmworker menJ Immigr Minor Health200681859719835002BrumittJReischRKrasnoselskyKWelchARuttRGarsideLIMcKayCSelf-reported musculoskeletal pain in Latino vineyard workersJ Agromedicine2011161728021213166Walker-BoneKPalmerKTMusculoskeletal disorders in farmers and farm workersOccup Med (Lond)200252844145012488514OhayonMMObservation of the natural evolution of insomnia in the American general population cohortSleep Med Clin200941879220161295LarsonSLClarkMREatonWWDepressive disorder as a long-term antecedent risk factor for incident back pain: a 13-year follow-up study from the Baltimore Epidemiological Catchment Area SamplePsychol Med200434221121914982127XiangHStallonesLKeefeTJBack pain and agricultural work among farmers: An analysis of the Colorado farm family health and hazard surveillance surveyAm J Ind Med19993533103169987565KarpJFScottJHouckPReynoldsCFKupferDJFrankEPain predicts longer time to remission during treatment of recurrent depressionJ Clin Psychiatry200566559159715889945ArcuryTAQuandtSAPreisserJSPredictors of incidence and prevalence of green tobacco sickness among Latino farmworkers in North Carolina, USAJ Epidemiol Community Health2001551181882411604438JohnsMWA new method for measuring daytime sleepiness: The Epworth Sleepiness ScaleSleep19911465405451798888JohnsMHockingBDaytime sleepiness and sleep habits of Australian workersSleep199720108448499415943PunjabiNMBandeen-RocheKYoungTPredictors of objective sleep tendency in the general populationSleep200326667868314572120MaycockGSleepiness and driving: the experience of heavy goods vehicle drivers in the UKJ Sleep Res1997642382449493523MaycockGSleepiness and driving: The experience of U.K. car driversAccid Anal Prev19972944534629248503TakahashiMIwakiriKSotoyamaMHirataMHisanagaNArm pain and daytime sleepiness among nursing home employeesIndustrial Health200644466967317085931SanfordSDLichsteinKLDurrenceHHRiedelBWTaylorDJBushAJThe influence of age, gender, ethnicity, and insomnia on Epworth Sleepiness Scores: A normative US populationSleep Med20067431932616713340BenbadisSRMaschaEPerryMCWolgamuthBRSmolleyLADinnerDSAssociation between the Epworth Sleepiness Scale and the Multiple Sleep Latency Test in a clinical populationAnn Intern Med19991304 Part 128929210068387DezeeKJJacksonJLHatzigeorgiouCKristoDThe Epworth Sleepiness Scale: relationship to sleep and mental disorders in a sleep clinicSleep Med20067432733216564218ArztMYoungTFinnLSkatrudJBRyanCMNewtonGEMakSParkerJDFlorasJSBradleyTDSleepiness and sleep in patients with both systolic heart failure and obstructive sleep apneaArch Intern Med2006166161716172216983049WalslebenJAKapurVKNewmanABShaharEBootzinRRRosenbergCEO’ConnorGNietoFJSleep and reported daytime sleepiness in normal subjects: The Sleep Heart Health StudySleep200427229329815124725KohoutFJBerkmanLFEvansDACornoni-HuntleyJTwo shorter forms of the CES-D Depression Symptoms IndexJ Aging Health19935217919310125443GrzywaczJGHoveyJDSeligmanLDArcuryTAQuandtSAEvaluating short-form versions of the CES-D for measuring depressive symptoms among immigrants from MexicoHisp J Behav Sci2006283404424WiehagenWJTurinFCErgonomic assessment of musculoskeletal risk factors at four mine sites: Underground coal, surface copper, surface phosphate, and underground limestoneU.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and HealthDHHS (NIOSH) Publication No 2004-159 Informational Circular 94752004Available at: http://www.cdc.gov/niosh/mining/pubs/pubreference/outputid82.htmAccessed Nov. 11, 2010OhayonMMPain sensitivity, depression, and sleep deprivation: links with serotoninergic dysfunctionJ Psychiatr Res200943161243124519914447BixlerEOVgontzasANLinH-MCalhounSLVela-BuenoAKalesAExcessive daytime sleepiness in a general population sample: the role of sleep apnea, age, obesity, diabetes, and depressionJ Clin Endocrinol Metab20059084510451515941867GrzywaczJGQuandtSAChenHIsonSKiangLVallejosQArcuryADepressive symptoms among Latino farmworkers across the agricultural season: structural and situational influencesCult Divers and Ethnic Minor Pyschol2010163335343GanderPHMarshallNSHarrisRReidPThe Epworth Sleepiness Scale: influence of age, ethnicity, and socioeconomic deprivation. Epworth Sleepiness scores of adults in New ZealandSleep200528224925316171250BuysseDJReynoldsCF3rdMonkTHBermanSRKupferDJThe Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and researchPsychiatry Res19892821932132748771NetzerNCStoohsRANetzerCMClarkKStrohlKPUsing the Berlin Questionnaire to identify patients at risk for the sleep apnea syndromeAnn Intern Med1999131748549110507956BastienCHVallièresAMorinCMValidation of the Insomnia Severity Index as an outcome measure for insomnia researchSleep Med20012429730711438246BaruchYResponse rate in academic studies: a comparative analysisHum Relations1999524421438

Participant Characteristics- Farmworkers, Eastern North Carolina, 2009.

Total SampleN = 300
N%
Gender
 Male28595.0
 Female155.0
Age
 18 to 24 years5919.7
 25 to 29 years3511.7
 30 to 39 years11036.7
 40 years and older9632.0
Educational Attainment
 0 to 6 years16153.7
 7 or more years13946.3
Years in Agriculture in the US
 1 year or less4113.7
 2 to 7 years14147.0
 8 or more years11839.3
Language Spoken*
 Spanish29999.7
 English3511.7
 Indigenous6020.0

Categories are not mutually exclusive

Descriptive Statistics and Inter-Correlations of Daytime Sleepiness, Depressive Symptoms, and Musculoskeletal Pain among Farmworkers in Eastern North Carolina, 2009

NMSD123
Daytime Sleepiness (ESS) (1)3005.103.251.00
Depressive Symptoms (CES-D) (2)2947.893.220.27***1.00
Musculoskeletal Pain (3)3001.352.09−0.15**0.091.00

p < .01

p < .001

Bivariate Associations between Farmworker Characteristics and Daytime Sleepiness, Depressive Symptoms, and Musculoskeletal Pain, Eastern North Carolina, 2009

ElevatedDaytimeSleepinessNon-ElevatedDaytimeSleepinessp-valueElevatedDepressiveSymptomsNon-ElevatedDepressiveSymptomsp-valueElevatedMusculoskeletalPainNon-ElevatedMusculoskeletalPainp-value
(ESS ≥ 10)(ESS < 10)(CES-D ≥ 10)(CES-D < 10)(≥ Weekly & ≥ Moderate Pain)(< Weekly of < Moderate Pain)
N=32 (10.7%)N=268 (89.3%)N = 82 (27.9%)N = 212 (72.1%)N = 16 (5.3%)N = 284 (94.7%)

%%%%%%
Gender
 Male3093.825595.10.657996.320094.30.411381.327295.80.01
 Female26.3134.933.7125.7318.8124.2
Age
 18 to 2413.15821.60.01911.05023.60.03212.55720.1NA
 25 to 29515.63011.21113.42411.300.03512.3
 30 to 39825.010238.12935.47937.3531.310537.0
 >= 401856.37829.13340.25927.8956.38730.6
Educational Attainment
 0 – 6 years1959.414253.00.495061.010850.90.071168.815052.80.29
 7+ years1340.612647.03239.010449.1531.313447.2
Years in Agriculture
 1 or less26.33914.60.011012.23114.60.92212.53913.70.68
 2 – 7 years1031.313148.93947.69846.2956.313246.5
 8+ years2062.59836.63340.28339.2531.311339.8
Language Spoken
 Spanish3196.9268100.0NA82100.021199.5NA16100.028399.6NA
 English721.92810.40.111214.6219.90.2516.33412.00.47
 Indigenous1031.35018.70.081315.94722.20.18318.85720.10.88

p-value for association between those who have and do not have elevated depressive level, those who do and do not have elevated daytime sleepiness, and those with elevated and non-elevated musculoskeletal pain, adjusting for camp