An Unmatched Case‐Control Study of Nearly Lethal Suicide Attempts in Houston,Texas: Research Methods and Measurements

T his article details the research methods and measurements used in conducting a population‐based, case‐control study of nearly lethal suicide attempts among persons aged 13–34 years, residing in Houston, Texas. From November 1992 to July 1995, we interviewed 153 case subjects presenting at one of three participating hospital emergency departments and used random digit dialing to identify 513 control subjects residing in the same catchment area in which cases were enlisted. Unlike most research in this area, this study was designed to extend our understanding of suicidal behavior and prevention activities beyond identification and treatment of depression and other mental illnesses. We discuss the overall strengths and weaknesses of our study design and conclude that this methodology is well suited for studying rare outcomes such as nearly lethal suicide.     

Help‐Seeking Behavior Prior to Nearly Lethal Suicide Attempts

T he association between help‐seeking and nearly lethal suicide attempts was evaluated using data from a population‐based, case‐control study of 153 13‐ to 34‐year‐old suicide attempt case‐patients treated at emergency departments in Houston, Texas, and a random sample of 513 control‐subjects. Measures of help‐seeking included whether the participant sought help for health/emotional problems in the past month, type of consultant contacted, and whether suicide was discussed during the interaction. Overall, friends/family were consulted most frequently (48%). After controlling for potential confounders, case‐patients were less likely than control‐subjects to seek help from any consultant (OR = 0.5, 95% CI = 0.3–0.8) or a professional (e.g., physician, counselor) consultant (OR = 0.5, 95% CI = 0.29–0.8). Among those who sought help, case‐patients were more likely than to discuss suicide (OR = 2.6, 95% CI = 1.2–5.4), particularly with professionals (OR = 11.8, 95% CI = 3.2–43.2). Our findings suggest that efforts to better understand the role of help‐seeking in suicide prevention, including help sought from family and friends, deserves further attention.     

Medical Conditions and Nearly Lethal Suicide Attempts

P hysical illness has been studied as a risk factor for suicidal behavior, but little is known about this relationship among younger persons. We conducted a population‐based, case‐control study in Houston, Texas, from November 1992 through September 1995. The final sample consisted of 153 case‐ and 513 control‐subjects aged 13 to 34 years. Case patients were identified at hospital emergency departments and met criteria for a nearly lethal suicide attempt. Control subjects were recruited via a random‐digit‐dial telephone survey. Case patients were more likely than controls to report having any serious medical conditions (crude OR = 3.23; 95% CI = 2.12–4.91). After controlling for age, race/ethnicity, alcoholism, depression, and hopelessness, the adjusted odds ratio for men was 4.76 (95% CI = 1.87–12.17), whereas the adjusted odds ratio for women was 1.60 (95% CI‐0.62–4.17), suggesting that young men with medical conditions are at increased risk for nearly lethal suicide attempts. Increased efforts to identify and appropriately refer these patients are needed.     

The Stiles summation index applied to heterochromatic brightness matching

The summation index technique introduced by Stiles has been applied to heterochromatic brightness matching in order to explain individual differences in luminous efficiency functions for brightness. Such functions were obtained for 2-deg and 10-deg fields from twelve subjects, and the difference between the two fields was compared with the macular pigment density tabulated in Wyszecki and Stiles's book. A summation index was obtained for red and green stimuli combinations and the results are expressed in the form of an equation with nonlinear coefficients. The same equation is applied to the brightness luminous efficiency functions and the individual differences in the efficiency function are interpreted as the result of different contributions of opponent chromatic channels to the perception of brightness.