Work Environment and Well-being of Staff Nurses in Government and Non Government Hospitals

Long-term effects and vulnerable groups

Gastrointestinal (GI) complaints are common in shift workers and could be due to changes in circadian rhythms of GI function, sleep deprivation leading to stress response and changes in immune function, or the types of foods that are available during these shifts.

Schernhammer and colleagues (2006) reported an increased risk of colon cancer in nurses working 3 or more nights per month for 15 or more years. Psychological complaints are frequently reported, including depression and other mood disturbances, personality changes, and relationship difficulties. A review of 17 studies suggests that shift work increases the risk for cardiovascular disease by 40 percent compared with day workers. Possible mechanisms include decreased glucose tolerance, insulin resistance, elevated cortisol levels, and increased sympathetic activity. In reproductive outcome studies concluded that shift work was associated with a modest increase in spontaneous abortion, preterm birth, and reduced fertility in women. The effect on reproduction in men was not analyzed due to an inadequate number of studies. A meta-analysis of 13 studies examining night work and breast cancer reported that night work was associated with a moderately elevated risk among women. The exposure to light at night reduces melatonin levels, increasing risks for cancer.

Shift work also may exacerbate preexisting chronic diseases, making it difficult to control symptoms and disease progression. Shift work interferes with treatment regimens that involve regular sleep times, avoiding sleep deprivation, controlling amounts and times of meals and exercise, or careful timing of medications that have circadian variations in effectiveness.

Sood suggests several conditions that may be exacerbated by shift work: unstable angina or history of myocardial infarction, hypertension, insulin-dependent diabetes, asthma, psychiatric illnesses, substance abuse, GI diseases, sleep disorders, and epilepsy requiring medication.

Costa adds to this list chronic renal impairment, thyroid and suprarenal pathologies, malignant tumors, and pregnancy. Aging is also associated with less tolerance of shift work, which may be due to age-related changes in sleep that may make it more difficult for older people to initiate and maintain sleep at different times of the day. These sleep changes may begin as early as the 30s and 40s, so some workers who initially adapted well to shift work during their younger years may show more symptoms as they grow older.
Caruso and colleagues reported in terms of long work hours, overtime was associated with poorer perceived general health, increased injury rates, more illnesses, or increased mortality in 16 of 22 recently published studies. Dembe and colleagues, examining data from the National Longitudinal Survey of Youth, found a dose-response relationship, such that as the number of work hours increased, injury rates increased correspondingly. Trinkoff and colleagues found that long work hours were related to the incidence of musculoskeletal injuries and needlesticks in nurses. It indicates that caution is needed in implementing schedules with extended work hours. Determining the number of work hours critically associated with risk for a specific job.