Reasons of refusal and drop out in a follow up study involving primigravidae in Pakistan.

OBJECTIVE: To determine the reasons underlying the refusals to participate and drop outs from a follow up study involving primigravidae. DESIGN: A descriptive study. METHODS: Aga Khan University and Aga Khan Hospital for Women, Karachi, jointly initiated a nested case-control study on primigravidae for determining the predictability of preeclampsia using various biochemical markers in blood. The protocol-eligible study subjects were counseled along with their accompanying family members to participate in the study. All women recruited in this study were followed up throughout their pregnancy till delivery. RESULTS: One thousand six hundred and sixty-five primigravidae were identified as the potential study subjects. Out of which, 1,307 (78.5%) consented and 358 (21.5%) refused to participate in the study. The most common reason underlying the refusal was inability to get permission from the family members (n=84; 34.4%) followed by fear of prick (n=51; 20.9%). For 114 refusals, either the reason was not mentioned by the counseled women (n=60) or the data was missing (n=54). Out of 1,307 women recruited in the research, only 611 (46.7%) women completed the study according to the prescribed protocol. Among the rest, 102 (7.8%) subsequently withdrew from the research, 503 (38.5%) were dropped out, and 91 (7.0%) were lost to follow up. CONCLUSIONS: Refusal to participate and drop out from the research program are two significant factors hindering the smooth flow of a study. In Pakistan, the major reason for the refusal by the protocol-eligible pregnant women for participating in a research program is the unwillingness of the family members.

Exposure assessment of lead from food and airborne dusts and biomonitoring in pregnant mothers, their fetus and siblings in Karachi, Pakistan and Shimotsuke, Japan.

AIM: Exposure assessment of lead (Pb) and Arsenic (As) from food, water, and house dust intake were assessed among pregnant women, their children and fetuses in Pakistan and Japan, as well as their body burden of the metals in their blood. METHOD: Fifty families which included a pregnant woman, a fetus and the 1-3-year-old siblings were recruited in Karachi and Khairpur in Pakistan, and Shimotsuke and Asahikawa in Japan, respectively. Their dietary exposure to Pb and As was measured in 3-day food duplicates and drinking water by ICP-MP. Pb in house dust and respirable dust was evaluated with an energy dispersive X-ray fluorescence spectrometry. Non-radioactive isotope Pb profiles of blood specimens will be compared with those of the exposure origins, such as food duplicates, respirable house dust, the soils nearby, and gasoline. RESULTS: Judging from the data collected and analyzed so far, contribution from dietary intake is highly correlated to higher body burden of Pb among Pakistani mothers. Additional data analyses will reveal the status of Pb and As body burden in Pakistani mothers, fetuses and their siblings, and causal sources of high body burden is delineated by Pb isotope profile analysis of different sources of Pb exposure.

Lead-associated deficits in stature, mental ability and behaviour in children in Karachi.

This study was conducted to evaluate the cumulative and steady-state lead burden in children from Karachi, an area of high lead exposure, and to assess the degree of damage to physical growth and mental ability related to lead exposure. A cross-sectional survey was conducted in seven primary schools from around Karachi. Shed primary teeth and blood samples were collected from students of grades I to III (age range 6-10 years) and were analysed for lead by atomic absorption spectrophotometry. Haemoglobin concentration, height, weight and head circumference were measured. IQ was estimated using Raven's Standard Progressive Matrices. Classroom behaviour was rated by teachers and school performance was estimated from the percentage mark in a school examination taken just before the date of the IQ test. Complete data were available for 138 children. Over 80% of children had lead levels above the safety limit set by the United States Centers for Disease Control and Prevention. The blood lead levels in boys did not differ significantly from that in girls. Significant differences were observed between the schools. Univariate analysis showed negative association of blood lead with haemoglobin, IQ and height. Tooth lead was negatively associated with height, classroom behaviour and performance. When adjusted for other confounding variables, blood lead was negatively associated with haemoglobin and IQ, whereas tooth lead was negatively associated only with classroom behaviour. Height was negatively associated with blood or tooth lead. These results were further supported when the upper and lower quintiles for blood or tooth lead were compared. Tooth lead level was not a better marker of lead poisoning than blood lead level in our study population. These data demonstrate the association of increased lead with impaired learning and adverse behaviour in Karachi children and call for strict government regulations to limit environmental lead burden.