Thiocyanate as an indicator of tobacco smoking.

This study demonstrates the suitability of serum thiocyanate as an indicator of tobacco smoke. The median serum level of smokers rises steadily from 51 μmol/liter in nonsmokers to 174 μmol/liter in smokers of more than 20 cigarettes/day. The method can be used in epidemiologic studies of smoking behavior and smoking cessation. To increase the accuracy of predicting smoking habits, this test can be used in conjunction with a determination of expired carbon monoxide.     

Serologic screening of infectious diseases in blood banks as an indicator of morbidity in the population

Screening tests of 62,814 blood donations carried out between October 85 and October 87 in all five blood banks of Goiania, Central Brazil, were analysed. The private institutions (3 blood banks) collected 80% of all donations and the remaining were collected by public blood banks. Seroprevalence of HIV, HBsAg, Chagas' disease and syphilis were compared with data obtained in the surveillance system and from previous surveys in an attempt to validate this source of health information. A seroprevalence of 0.07% for AIDS (one ELISA test) was calculated, which may suggest the presence of 1900 infected individuals, in the population of the State of Goiás as a whole. This figure seems reasonably close to the official data obtained by compulsory notification. For Chagas' disease, hepatitis B and syphilis seroprevalence of 3.3%, 1.3% and 4.1% were obtained, respectively. The potential usefulness and the limitations of screening in blood banks as a source of reliable morbidity indicator is discussed.     

Certified sick leave as a non-specific morbidity indicator: a case-referent study among nurses.

A case-referent study assessed the association between medically certified sick leave from work and some occupational characteristics--namely, two work load indices (nurse patient ratio and patients' average duration of stay) and hospital and care unit. Study participants were nurses from seven general hospitals in Québec City who had been employed for at least six months at the time of study. Cases (n = 184) experienced at least one episode of medically certified sick leave for a diagnosis "most likely to be related to work load" between 1 January 1984 and 31 May 1987. Referents (n = 1165) were chosen from subjects who had no such leave, whatever the medical reason, and were matched to cases by the incidence density sampling method. Occupational data were collected from employment records and administrative files. Analysis was by multiple logistic regression. Significant associations were found between sick leave and nurse-patient ratio among head nurses, patient's duration of stay, and one hospital. Sick leave was more frequent among full time permanent nurses and among those on night and evening schedules. These associations were independent of age, duration of service in this hospital or in the actual job assignment, and care unit. This study supports the relevance of using sick leave as a non-specific indicator of health out-comes.     

Certified sick leave as a non-specific morbidity indicator: a case-referent study among nurses.

A case-referent study assessed the association between medically certified sick leave from work and some occupational characteristics--namely, two work load indices (nurse patient ratio and patients' average duration of stay) and hospital and care unit. Study participants were nurses from seven general hospitals in Québec City who had been employed for at least six months at the time of study. Cases (n = 184) experienced at least one episode of medically certified sick leave for a diagnosis "most likely to be related to work load" between 1 January 1984 and 31 May 1987. Referents (n = 1165) were chosen from subjects who had no such leave, whatever the medical reason, and were matched to cases by the incidence density sampling method. Occupational data were collected from employment records and administrative files. Analysis was by multiple logistic regression. Significant associations were found between sick leave and nurse-patient ratio among head nurses, patient's duration of stay, and one hospital. Sick leave was more frequent among full time permanent nurses and among those on night and evening schedules. These associations were independent of age, duration of service in this hospital or in the actual job assignment, and care unit. This study supports the relevance of using sick leave as a non-specific indicator of health out-comes.     

Estimating prevalence of community morbidity due to intestinal helminths: prevalence of infection as an indicator of the prevalence of disease.

The rational design of helminth control programmes for endemic areas requires that the limited resources be focused on the communities in greatest need. The process of locality-targetting would be facilitated by a simple, inexpensive method of assessing morbidity at the community level. This paper describes how a simple model of the distribution of infection in human populations can use infection prevalence data to predict the proportion of heavy, and potentially clinically significant, infections in a community. Analysis of observed data for Ascaris lumbricoides indicates that the risk of clinical ascariasis increases non-linearly with the prevalence of infection. The predicted prevalence of morbidity is low up to approximately 60% prevalence of infection, but increases very rapidly thereafter. Analyses of data for Trichuris trichiura, Schistosoma mansoni, S. haematobium and the hookworms suggests qualitatively similar patterns. The application of the model in predicting resource requirements for control is illustrated using infection prevalence data for A. lumbricoides in Brazil.     

Birth weight of neonates as an indicator of morbidity and mortality in adult age and factors which influence it

In 28 neonates born by spontaneous delivery to healthy mothers with a normal course of gestation venous umbilical blood was examined to assess the immunoreactive insulin concentration. Moreover, the birth weight of the neonates was recorded, the weight increment of the mother during pregnancy and the body mass index at the end of gestation. By means of a questionnaire and the computer programme Progana the dietary intake of the mothers at the end of pregnancy was assessed and compared with recommended allowances. The assembled data were evaluated statistically by assessment of the correlation coefficient. The investigation revealed that the birth weight of the neonates in the group does not correlate with the immunoreactive insulin concentration in umbilical venous blood. Although the dietary intake of the mothers at the end of pregnancy is not ideal (fat and cholesterol intake predominates over carbohydrate and protein intake), it does not correlate with the birth weight of the neonates nor with the immunoreactive insulin concentration in umbilical venous blood. From these results the conclusion is drawn that neonates with a low birth weight do not have a higher plasma insulin concentration after delivery and that the mother's diet at the end of pregnancy does not influence the birth weight and insulin level in neonates.     

Life expectancy as an indicator of outcome

Usually survival studies evaluate the percentage of subjects alive or disease-free at a given point in time (cumulative survival percentage). These studies require a lengthy period both for follow up and for the collection of an exhaustive number of cases. In addition, for cancer types with a sharp gradient of cumulative mortality, the estimate may be unstable. On the database of children with Acute Lymphoblastic Leukaemia (ALL) collected by the Childhood Cancer Registry of Piedmont (CCRP) in 1979-1991, we have estimated an alternative time-dimensional index to estimate both patients' life expectancy of patient and number of years gained to death. These estimates have been compared in subsets of the database corresponding to different periods of diagnosis and efficacy of treatment. Life expectancy has been evaluated as the area under the survival curve, on the assumption that after a number of years since diagnosis, survivors have the same mortality rates of the general population. Clinicians are invited to take into consideration the approach described in the present note.     

Macrocytosis as an indicator of human disease

Adult patients with macrocytosis, defined as a mean corpuscular volume (MCV) greater than 100 femtoliters, were studied to assess the importance of an elevated MCV. After eliminating pregnant and postpartum patients and patients receiving medications known to cause macrocytosis (e.g., phenytoin, zidovudine, and chemotherapeutic agents), 80 patients were identified and studied. Sixty-seven diagnoses were made in 56 patients. These diagnoses were, in descending order: alcoholism, hematological disorders, habitual drinking, B12 deficiency, chronic liver disease, folic acid deficiency, hypothyroidism, anorexia nervosa, and reticulocytosis. While an elevated MCV is neither sensitive nor specific for any one disease state, an elevated MCV should raise suspicions of underlying pathology.     

Analysing morbidity determination with flawed data: the case of dysentery in regional India

A method is suggested for removing measurement error from morbidity data collected in Third World countries. The method assumes the existence of diseases which are independent of socio-economic factors and exploits observed correlations between these disease and these factors to construct an index of measurement error. This index may be used as an explanatory variable in the analysis of other diseases which are hypothesised to have socio-economic causes which are the object of research. The method is applied to statewide data for India where the index of measurement error is based on influenza data which is then used to isolate the socio-economic factors that influenced dysentery.     

The hospital multistay rate as an indicator of quality of care.

OBJECTIVES: To evaluate the hospital multistay rate to determine if it has the attributes necessary for a performance indicator that can be applied to administrative databases. DATA SOURCES/STUDY SETTING: The fiscal year 1994 Veterans Affairs Patient Treatment File (PTF), which contains discharge data on all VA inpatients. STUDY DESIGN: Using a retrospective study design, we assessed cross-hospital variation in (a) the multistay rate and (b) the standardized multistay ratio. A hospital's multistay rate is the observed average number of hospitalizations for patients with one or more hospital stays. A hospital's standardized multistay ratio is the ratio of the geometric mean of the observed number of hospitalizations per patient to the geometric mean of the expected number of hospitalizations per patient, conditional on the types of patients admitted to that hospital. DATA COLLECTION/EXTRACTION METHODS: Discharge data were extracted for the 135,434 VA patients who had one or more admissions in one of seven disease groups. PRINCIPAL FINDINGS: We found that 17.3 percent (28,300) of the admissions in the seven disease categories were readmissions. The average number of stays per person (multistay rate) for an average of seven months of follow-up ranged from 1.15 to 1.45 across the disease categories. The maximum standardized multistay ratio ranged from 1.12 to 1.39. CONCLUSIONS: This study has shown that the hospital multistay rate offers sufficient ease of measurement, frequency, and variation to potentially serve as a performance indicator.     

Validity of anaesthetic complication coding data as a clinical indicator

Clinical indicators using routinely collected International Statistical Classification of Diseases, Australian Modification (ICD-10-AM) data offer promise as tools for improvement of quality. The ICD-10-AM is the coding system used by Australian administrators to summarise information from the clinical record to describe a patient's hospital encounter. The use of anaesthesia complications as coded by this system has been proposed by two jurisdictions as a monitor of the quality of anaesthetic services. We undertook a review of cases identified by such indicators in a large tertiary hospital. Our results indicate the anaesthesia indicator dataset proposed by the Victorian and Queensland Health departments appears to have little clinical or quality improvement relevance.     

Sperm as an indicator of reproductive risk among petroleum refinery workers.

A questionnaire study of men in a wastewater treatment plant of a petroleum refinery showed twice the rate of fetal loss in the period during employment in the plant compared with the periods before and after. Questions regarding the interpretation of that study and continuing concern about reproductive risk prompted us to perform a cross sectional evaluation of sperm concentration and morphology. After adjustment for an abstinence period, the mean sperm concentration of the 74 unexposed men did not differ significantly from that of the 34 exposed men (79.9 million/cm3 v 68.2 million/cm3, p(1) = 0.16). The two groups also had a similar proportion of sperm with abnormal morphology (49.1% v 44.5%, p(1) = 0.94). This lack of association remained when degree of exposure, age, use of alcohol and marijuana, past illness or fever, use of baths or sauna, and history of urological problems were considered. These results are most consistent with the absence of sperm mediated reproductive problems.