Beyond 'find and fix': improving quality and safety through resilient healthcare systems.

OBJECTIVE: The aim was to develop a method based on resilient healthcare principles to proactively identify system vulnerabilities and quality improvement interventions. DESIGN: Ethnographic methods to understand work as it is done in practice using concepts from resilient healthcare, the Concepts for Applying Resilience Engineering model and the four key activities that are proposed to underpin resilient performance-anticipating, monitoring, responding and learning. SETTING: Accident and Emergency Department (ED) and the Older People's Unit (OPU) of a large teaching hospital in central London. PARTICIPANTS: ED-observations 104 h, and 14 staff interviews. OPU-observations 60 h, and 15 staff interviews. RESULTS: Data were analysed to identify targets for quality improvement. In the OPU, discharge was a complex and variable process that was difficult to monitor. A system to integrate information and clearly show progress towards discharge was needed. In the ED, patient flow was identified as a complex high-intensity activity that was not supported by the existing data systems. The need for a system to integrate and display information about both patient and organizational factors was identified. In both settings, adaptive capacity was limited by the absence of systems to monitor the work environment. CONCLUSIONS: The study showed that using resilient healthcare principles to inform quality improvement was feasible and focused attention on challenges that had not been addressed by traditional quality improvement practices. Monitoring patient and workflow in both the ED and the OPU was identified as a priority for supporting staff to manage the complexity of the work.

Implementing resilience engineering for healthcare quality improvement using the CARE model: a feasibility study protocol.

BACKGROUND: Resilience engineering (RE) is an emerging perspective on safety in complex adaptive systems that emphasises how outcomes emerge from the complexity of the clinical environment. Complexity creates the need for flexible adaptation to achieve outcomes. RE focuses on understanding the nature of adaptations, learning from success and increasing adaptive capacity. Although the philosophy is clear, progress in applying the ideas to quality improvement has been slow. The aim of this study is to test the feasibility of translating RE concepts into practical methods to improve quality by designing, implementing and evaluating interventions based on RE theory. The CARE model operationalises the key concepts and their relationships to guide the empirical investigation. METHODS: The settings are the Emergency Department and the Older Person's Unit in a large London teaching hospital. Phases 1 and 2 of our work, leading to the development of interventions to improve the quality of care, are described in this paper. Ethical approval has been granted for these phases. Phase 1 will use ethnographic methods, including observation of work practices and interviews with staff, to understand adaptations and outcomes. The findings will be used to collaboratively design, with clinical staff in interactive design workshops, interventions to improve the quality of care. The evaluation phase will be designed and submitted for ethical approval when the outcomes of phases 1 and 2 are known. DISCUSSION: Study outcomes will be knowledge about the feasibility of applying RE to improve quality, the development of RE theory and a validated model of resilience in clinical work which can be used to guide other applications. Tools, methods and practical guidance for practitioners will also be produced, as well as specific knowledge of the potential effectiveness of the implemented interventions in emergency and older people's care. Further studies to test the application of RE at a larger scale will be required, including studies of other healthcare settings, organisational contexts and different interventions.

Risk factors for active trachoma in The Gambia.

Trachoma has been endemic in The Gambia for decades but national surveys indicate that the prevalence is falling. Risk factor data can help guide trachoma control efforts. This study investigated risk factors for active trachoma and ocular Chlamydia trachomatis infection in children aged below 10 years in two Gambian regions. The overall prevalence of C. trachomatis infection was only 0.3% (3/950) compared with 10.4% (311/2990) for active trachoma, therefore analyses were only performed for active trachoma. After adjustment, increased risk of trachoma was associated with being aged 1-2 years (odds ratio (OR) 2.20, 95% CI 1.07-4.52) and 3-5 years (OR 3.62, 95% CI 1.80-7.25) compared with <1 year, nasal discharge (OR 2.07, 95% CI 1.53-2.81), ocular discharge (OR 2.68, 95% CI 1.76-4.09) and there being at least one other child in the household with active trachoma (OR 11.28, 95% CI 8.31-15.31). Compared with other occupations, children of traders had reduced risk (OR 0.53, 95% CI 0.30-0.94). At the household level, only the presence of another child in the household with active trachoma was associated with increased risk of active trachoma, suggesting that current trachoma control interventions are effective at this level. In contrast, child-level factors were associated with increased risk after adjustment, indicating a need to increase control efforts at the child level.

Interaction between saquinavir soft-gel and rifabutin in patients infected with HIV.

AIMS: To evaluate the potential pharmacokinetic interaction between the HIV protease inhibitor saquinavir and rifabutin. METHODS: Fourteen HIV-infected patients provided full steady-state pharmacokinetic profiles following administration of rifabutin alone (300 mg once daily) or saquinavir soft-gel formulation (1200 mg three times daily) plus rifabutin (300 mg once daily) in this open label, partially randomized study. RESULTS: Coadministration of saquinavir and rifabutin resulted in a reduction in saquinavir AUC(0,8 h) and C(max)(0,8 h) of 47% (95% CI 30, 60%) and 39% (95% CI 11, 59%), respectively. Rifabutin AUC(0,24 h) and C(max)(0,24 h) was increased by an average of 44% (95% CI 17, 78%) and 45% (95% CI 14, 85%), respectively. Saquinavir in combination with rifabutin was well tolerated. Gastrointestinal intolerance and asymptomatic increases in liver enzymes were the only adverse events of note. CONCLUSIONS: Administration of rifabutin with saquinavir may decrease the efficacy of this HIV protease inhibitor.

Saquinavir and ritonavir pharmacokinetics following combined ritonavir and saquinavir (soft gelatin capsules) administration.

AIMS: To investigate the influence of combined ritonavir (RTV) and saquinavir (soft-gelatin capsule formulation; SQV) on systemic exposure to SQV with a view to optimizing the dosing regimen of combined RTV and SQV antiretroviral therapy. METHODS: In this open labelled, randomized, parallel group study, SQV and RTV were administered twice daily for 14 days to groups of eight healthy subjects. The two antiretrovirals were either administered alone (800 mg SQV, regimen A, and 400 mg RTV, B) or in combination at various dose levels (RTV : SQV: 400 : 400 mg, C; 300 : 600 mg, D; 200 : 800 mg, E; 300 : 800 mg, F; 400 : 800 mg, G; and 400 : 600 mg, H). Pharmacokinetic parameters of saquinavir and ritonavir were determined and adverse events, vital signs, and clinical laboratory variables recorded. RESULTS: RTV substantially increased the plasma concentration of saquinavir for all dose combinations, compared with SQV alone. Based on the primary statistical analysis there was an overall 17-, 22-, and 23-fold increase in saquinavir AUC(0,24 h) on day 14 with regimens E, F, and G, respectively (with confidence intervals of 10-30, 13-37, and 13-39). The lowest combination dose of RTV (200 : 800 mg; E) significantly increased the saquinavir AUC(0,24 h) from below 5 to 57 microg ml(-1) h, which was higher than the exposure obtained with the 400 : 400 mg twice daily regimen (i.e. 36 microg ml(-1) h). RTV also reduced intersubject variability in AUC(0,24 h) for saquinavir from 105% to 32-68%, and C(max)(0,24 h) from 124% to 30-49%. In contrast, SQV showed no clinically significant effect on the pharmacokinetics of ritonavir. The combination regimens were well tolerated, with the least number of adverse events recorded for the 200 : 800 mg (RTV : SQV) combination regimen. CONCLUSIONS: RTV significantly increases saquinavir exposure as a consequence of inhibiting SQV metabolism and possibly P-glycoprotein efflux. Pharmacokinetic and safety profiles obtained in the current study indicate that the use of a combination with a lower dose of RTV and a higher dose of SQV than the 400 : 400 mg combination frequently used in clinical practice should be further explored.

A 30-year follow-up of the Dallas Bedrest and Training Study: I. Effect of age on the cardiovascular response to exercise.

BACKGROUND: Cardiovascular capacity declines with aging, as evidenced by declining maximal oxygen uptake (VO(2)max ), with little known about the specific mechanisms of this decline. Our study objective was to assess the effect of a 30-year interval on body composition and cardiovascular response to acute exercise in 5 healthy subjects originally evaluated in 1966. METHODS AND RESULTS: Anthropometric parameters and the cardiovascular response to acute maximal exercise were assessed with noninvasive techniques. On average, body weight increased 25% (77 versus 100 kg) and percent body fat increased 100% (14% versus 28%), with little change in fat-free mass (66 versus 72 kg). On average, VO(2)max decreased 11% (3.30 versus 2.90 L/min). Likewise, VO(2)max decreased when indexed to total body mass (43 versus 31 mL. kg(-1). min(-1)) or fat-free mass (50 versus 43 mL/kg fat-free mass per minute). Maximal heart rate declined 6% (193 versus 181 bpm) and maximal stroke volume increased 16% (104 versus 121 mL), with no difference observed in maximal cardiac output (20.0 versus 21.4 L/min). Maximal AV oxygen difference declined 15% (16.2 versus 13.8 vol%) and accounted for the entire decrease in cardiovascular capacity. CONCLUSIONS: Cardiovascular capacity declined over the 30-year study interval in these 5 middle-aged men primarily because of an impaired efficiency of maximal peripheral oxygen extraction. Maximal cardiac output was maintained with a decline in maximal heart rate compensated for by an increased maximal stroke volume. Most notably, 3 weeks of bedrest in these same men at 20 years of age (1966) had a more profound impact on physical work capacity than did 3 decades of aging.

A 30-year follow-up of the Dallas Bedrest and Training Study: II. Effect of age on cardiovascular adaptation to exercise training.

BACKGROUND: Aerobic power declines with age. The degree to which this decline is reversible remains unclear. In a 30-year longitudinal follow-up study, the cardiovascular adaptations to exercise training in 5 middle-aged men previously trained in 1966 were evaluated to assess the degree to which the age-associated decline in aerobic power is attributable to deconditioning and to gain insight into the specific mechanisms involved. Methods and Results-- The cardiovascular response to acute submaximal and maximal exercise were assessed before and after a 6-month endurance training program. On average, VO(2max) increased 14% (2.9 versus 3.3 L/min), achieving the level observed at the baseline evaluations 30 years before. Likewise, VO(2max) increased 16% when indexed to total body mass (31 versus 36 mL/kg per minute) or fat-free mass (44 versus 51 mL/kg fat-free mass per minute). Maximal heart rate declined (181 versus 171 beats/min) and maximal stroke volume increased (121 versus 129 mL) after training, with no change in maximal cardiac output (21.4 versus 21.7 L/min); submaximal heart rates also declined to a similar degree. Maximal AVDO(2) increased by 10% (13.8 versus 15.2 vol%) and accounted for the entire improvement of aerobic power associated with training. CONCLUSIONS: One hundred percent of the age-related decline in aerobic power among these 5 middle-aged men occurring over 30 years was reversed by a 6-month endurance training program. However, no subject achieved the same maximal VO(2) attained after training 30 years earlier, despite a similar relative training load. The improved aerobic power after training was primarily the result of peripheral adaptation, with no effective improvement in maximal oxygen delivery.

Combination therapy with saquinavir soft gelatin capsules in children with human immunodeficiency virus infection.

OBJECTIVES: To evaluate the pharmacokinetics, tolerance, safety and antiviral activity of the HIV protease inhibitor, saquinavir, formulated as soft gelatin capsules (SQV-SGC), given in combination with nucleoside antiretroviral agents (NRTIs) with or without nelfinavir in HIV-infected children. METHODS: This was an open label study of HIV-infected children ages 3 to 16 years, conducted in two parts. In Part 1 of the study 14 children were treated orally with SQV-SGC (initially given in three 33-mg/kg doses daily; dosage adjusted to 50 mg/kg three times daily based on initial pharmacokinetics) and two NRTIs. Addition of nelfinavir was permitted for children who did not achieve a predetermined steady state target plasma saquinavir exposure. In Part 2 a new group of 13 children received SQV-SGC (33 mg/kg three times daily) in combination with nelfinavir and one or two NRTIs. Pharmacokinetics were assessed after the first dose and 4 weeks into treatment (steady state). Patients were treated for 72 and 48 weeks in Parts 1 and 2, respectively. RESULTS: Most adverse events were mild; the most commonly reported were diarrhea, abdominal discomfort and headache. Two children were withdrawn from the study because of adverse events (one each of nausea and dysphagia) related to the study treatment. There were no deaths or serious adverse events attributed to the study medication. Steady state saquinavir area under the plasma concentration vs. time curves (AUC24) were 6,210 and 11,010 ng/h/ml for Parts 1 and 2, respectively. Compared with baseline measurements median changes in plasma HIV RNA concentrations were -2.12 log10 copies/ml [5 of 14 (36%) with HIV RNA <50 copies/ml) (Week 72)] and -2.58 log10 copies/ml [8 of 13 (62%) <50 copies/ml) (Week 48)] in Parts 1 and 2, respectively. The median changes in CD4+ lymphocyte count were +292 and +154 cells/microl for Parts 1 and 2, respectively. Genotypic resistance assays revealed a low frequency of saquinavir-associated resistance mutations after 48 weeks of therapy, with only 2 of 27 children having substitutions at positions 48V and/or 90M. CONCLUSIONS: Combination therapy with SQV-SGC was well-tolerated and safe in HIV-infected children, and antiviral activity was observed. Saquinavir plasma concentrations were lower than expected, particularly for Part 1 (SQV-SGC plus NRTIs), but addition of nelfinavir increased saquinavir exposures.

Characterization of the MHC class I region of the Japanese pufferfish (Fugu rubripes).

A BAC map of the Japanese pufferfish (Fugu) MHC class I region was constructed using a mixture of sequence scanning and sequence-tagged site mapping methodologies. The Fugu MHC class Ia genes are linked to genes which are found within the human classical MHC class II and extended class II regions, a situation which has been found in the MHC of all teleosts mapped so far. The 300-kb contig comprises 24 MHC-related genes and is bounded by six non-MHC genes, which are thought to represent an evolutionary breakpoint within the region. Comparative analysis with both human and zebrafish MHC maps indicates two blocks of genes (KNSL2, ZNF297, DAXX, TAPBP, FLOTILLIN; and PSMB8, PSMB10, PSMB9, ABCB3, FABGL, BRD2, COL11A2, RXRB) which have remained linked over 400 million years and may represent an ancestral arrangement of the vertebrate MHC. Zebrafish and Fugu diverged between 100-200 million years ago and differences exist between these two fish species. The position and number of MHC class Ia genes is not conserved between species, there is an inversion of a block of nine genes centering on the PSMB cluster, and additional genes are present in zebrafish coding for a transport-associated protein and a beta proteasome subunit. The extent of these differences has implications for the extrapolation of fish model organism data to commercial aquaculture species. The data presented here represent the most extensive analysis of a fish MHC class Ia region described so far and clearly delimit the extent of this region in Fugu and, potentially, all teleosts.

High-density lipoprotein cholesterol and vascular stiffness at baseline in the activity counseling trial.

In a middle-aged patient population, age was associated with stiffer vessels and high-density lipoprotein cholesterol with more elastic vessels. High-density lipoprotein cholesterol may be an indirect indicator of aerobic capacity or of less atherosclerosis, suggesting mechanisms for preserving vascular integrity.

Population pharmacokinetics of levodopa in patients with Parkinson's disease treated with tolcapone.

OBJECTIVE: To use pharmacostatistical models to evaluate the overall exposure of patients with Parkinson's disease to levodopa in the presence and absence of tolcapone. METHODS: Four hundred twelve patients with Parkinson's disease with fluctuating and nonfluctuating responses to levodopa participated in three multicentered, parallel, double-blind, placebo-controlled dose-finding studies and received either placebo or tolcapone in addition to levodopa-decarboxylase inhibitor therapy. Sparse blood samples were obtained from 393 patients for levodopa and 3-O-methyldopa assay, and the data were analyzed with use of the NONMEM program. RESULTS: The fraction of levodopa metabolized to 3-O-methyldopa was substantially reduced by the co-administration of tolcapone (by 65%, 74%, and 84% with tolcapone doses of 50, 200, and 400 mg, respectively, in fluctuators, and by 50% and 90% with doses of 200 and 400 mg, respectively, in nonfluctuators). This led to an overall reduction in levodopa clearance (CL) of approximately 15% to 25% in fluctuators and 20% to 30% in nonfluctuators. Because this was partly compensated for by a reduction in levodopa dose in these studies, the total daily exposure of patients to levodopa was only slightly increased (11% to 16%). The peak-trough fluctuations of plasma levodopa (Cmax-Cmin) were reduced in both populations in a dose-dependent fashion. CONCLUSIONS: Tolcapone effectively inhibited the formation of 3-O-methyldopa and resulted in a decrease in levodopa CL. The consequent increase in levodopa bioavailability was mostly offset by reductions in levodopa dose. It is possible that decreased fluctuations in plasma levodopa concentrations rather than increased levodopa exposure may explain the clinical benefits obtained with tolcapone.

Population pharmacokinetics of tolcapone in parkinsonian patients in dose finding studies.

AIMS: To use pharmacostatistical models to characterize tolcapone's pharmacokinetics in parkinsonian patients, and to identify any demographic subpopulations which may be at risk of either under- or over-exposure to this catechol-O-methyltransferase (COMT) inhibitor. METHODS: Four hundred and twelve patients participated in three multicentre, parallel, double-blind, placebo-controlled, dose-finding studies and received either placebo or tolcapone (50, 200 or 400 mg three times daily) in addition to levodopa/decarboxylase inhibitor therapy. Sparse blood samples were obtained from 275 patients for tolcapone assay and the concentrations (1414 in total) were analysed using the NONMEM program. RESULTS: The pharmacokinetic model which best described the data was a two-compartment open model with first-order absorption and possibly a lag-time. Tolcapone pharmacokinetics were shown to be stable, with no systematic trend between 2 and 6 weeks of treatment. The absorption of the drug was shown to be rapid and concomitant food intake had only a minor effect on the relative bioavailability (10-20% reduction compared with fasting). The overall clearance of tolcapone could be estimated with good precision (approximately 4. 5-5 l h-1 ), and none of the investigated covariates (e.g. sex, age, body weight) had any clinically significant influence on this parameter. The volume of distribution showed relatively high variability and was calculated to be approximately 30 l, leading to an estimated half-life in patients of approximately 5-8 h. CONCLUSIONS: Using sparse concentrations and mixed effect-effects modelling analysis it is possible to describe the pharmacokinetics of tolcapone in parkinsonian populations. The parameter estimates obtained agreed with those obtained from conventional pharmacokinetic studies and no subpopulation was shown to be at risk of either under- or over-exposure to tolcapone.

Abnormal metabolism of free fatty acids in hypertriglyceridaemic men: apparent insulin resistance of adipose tissue.

OBJECTIVE: There is growing evidence that endogenous hypertriglyceridaemia is frequently accompanied by a state of insulin resistance. The present study was performed to determine whether patients with primary endogenous hypertriglyceridaemia commonly have abnormalities in plasma concentrations and turnover rates of free fatty acids (FFA), which could reflect a state of insulin resistance in adipose tissue and could account for raised plasma triglycerides. DESIGN: Hypertriglyceridaemic and normotriglyceridemic control patients underwent measurements of plasma concentrations and turnover rates of FFA. Fat weights in both groups were determined by hydrodensitometry, and fat distribution was assessed by skin-folds and measurement of waist and hip circumferences. Other measurements included plasma glucose, insulin, lipids, and lipoproteins. SUBJECTS: Fifteen men with normal plasma triglycerides and 21 men with primary endogenous hypertriglyceridaemia were studied. Men in both groups varied in body weights and total fat weights, but total fat weights were entirely overlapping for the two groups. Waist-to-hip ratios and waist circumferences also were similar for the two groups. RESULTS: For any total body fat content or waist circumference, most hypertriglyceridaemia patients had higher mean plasma concentrations of FFA and higher turnover rates (flux) for FFA than did normotriglyceridemic patients. Hypertriglyceridaemic patients also had higher fasting insulin concentrations for a given body fat content. In general, both FFA flux and plasma insulin levels were positively correlated with plasma concentrations of triglyceride and inversely with high density lipoprotein (HDL) cholesterol. CONCLUSIONS: These studies indicate that many patients with primary endogenous hypertriglyceridaemia have increased flux of FFA and hyperinsulinemia that cannot be explained either by increased total body fat content or by greater waist circumferences than observed in normotriglyceridemic patients.

Relationship between insulin sensitivity, hyperinsulinemia, and insulin-mediated sympathetic activation in normotensive and hypertensive subjects.

The adrenergic response to high physiological hyperinsulinemia was studied in 39 hypertensive subjects (28 men and 11 women) and 25 normal volunteers (15 men and 10 women), using the euglycemic clamp technique. Control studies using 0.45% saline infusions (sham studies) were also performed. Before and during the clamp procedure, plasma norepinephrine (NE) and epinephrine (E) were measured using a high performance liquid chromatographic method (HPLC). The association between the increment in NE and E levels and insulin sensitivity, steady-state insulin level during the clamps, waist to hip ratio (WHR), baseline NE levels and gender was studied. NE levels increased during the hyperinsulinemic period (mean increase 46 +/- 6 pmol P < .001 upsilon baseline and P < .01 upsilon sham studies). E levels did not differ between the insulin clamps and the sham studies. Insulin sensitivity was not significantly associated with the increment in NE. Hypertensive subjects had a higher NE increase than the normotensive individuals (55 +/- 7 upsilon 30 +/- 10 pmol, P = .03), but also had higher insulin levels during the clamps (839 +/- 43 upsilon 522 +/- 38 pmol, P < .001). Insulin levels accounted for most of the differences in NE increase between the normotensive and hypertensive groups. Gender, adiposity and WHR were also associated with NE increment. We conclude that the insulin mediated sympathetic activation is not affected in the presence of decreased insulin sensitivity for glucose utilization. The greater degree of sympathetic activation observed in hypertensive subjects is a function of the level of insulinemia obtained during the clamps.

AIDS in Côte d'Ivoire--ten years on.

AIDS is a world-wide health problem with a profile which varies widely. Côte d'Ivoire is one of the hardest hit countries in Africa. Since the declaration of the first cases in 1985, more than 18 600 cases have been diagnosed. Many initiatives have already been undertaken in the context of the government's National Programme Against AIDS, as well as by private institutions and individuals. However, much remains to be done, against heavy odds. Hôpital Protestant de Dabou (HPD) is one of the four major centres dealing with AIDS, and has itself declared more than 3000 cases since 1987. Since 1991 it has had a team dedicated to dealing with the multiple needs of people infected with HIV and their families, and more than 2000 patients have benefited from this support. This paper reports on the experience of this programme and draws lessons for the future.

The effect of running on serum and red cell ferritin. A longitudinal comparison.

It is unclear whether running can affect iron stores. Results using the serum ferritin assay (SER FER) have been conflicting. Decreased red cell ferritin (RBC FER) values (< or = 4 ag/RBC) occur in iron depleted or inflammatory states. We compared the longitudinal changes of hemoglobin (Hb), SER FER, RBC FER, % saturation of total iron binding capacity (% sat TIBC), and daily dietary intake in 27 runners during a training program. These parameters were measured at days 0, 49 (range 48-52), and 115 (range 85-120). No significant changes occurred in the SER FER, % sat TIBC and Hb determinations throughout the study. Overall the RBC FER values trended down (mean values 11.7 ag/RBC to 7.7 ag/RBC; p = 0.06). Fifteen runners (56%) acquired RBC FER values in the iron deficient range (mean 6.8 ag/RBC to 2.4 ag/RBC; p < 0.05). These values differed significantly from the remaining 12 runners (mean 17.3 ag/RBC to 14.7 ag/RBC). The decline in RBC FER into the iron deficient range was primarily seen in a subset of runners who began with a RBC FER value < or = 10 ag/RBC (positive predictive value 0.79) and was independent of iron intake. We conclude that ferritin can be affected by running as recognized by the red cell ferritin assay. Moreover our results suggest that this decrease in red cell ferritin is likely a function of defective iron utilization rather than total body iron deficiency. A potential consideration is that this fall may occur as a result of repetitive running-associated injury and inflammation.

Inheritance of osmotic adjustment to water stress in three grain sorghum crosses.

Water stress is one of the major constraints to the grain yield of sorghum in tropical and sub-tropical areas of the world. Osmotic adjustment has been widely proposed as a plant attribute that confers adaptation to water stress. The inheritance of osmotic adjustment to water stress was investigated in a series of generations derived from the three possible bi-parental crosses between two inbred sorghum lines with a high capacity for osmotic adjustment (Tx2813 and TAM422; high-OA lines) and one with a low capacity (QL27; low-OA line). Broad-sense heritability on a single-plant basis was generally found to be high. Analysis of segregation ratios by the mixture method of clustering identified two independent major genes for high osmotic adjustment. The line Tx2813 possessed a recessive gene which is given the symbol oa1; the line TAM422 possessed an additive gene which is given the symbol OA2. There was some evidence that there may be other minor genes which influence the expression of osmotic adjustment in these crosses as two putative transgressive segregants, with higher osmotic adjustment than the parents, were identified from the cross between Tx2813 and TAM422. Populations of recombinant inbred lines were developed and characterised for osmotic adjustment for two of the crosses (QL27 x TAM422, low-OA x high-OA; Tx2813 x TAM422, high-oal x high-OA2). These will be used to conduct experiments which test hypotheses about the contribution of the high-osmotic-adjustment genes to the grain yield of sorghum under a range of water-stress conditions.